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      "title": "Latest Arxiv Papers In Astrophysics B |2019-07-21",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Cosmology And Nongalactic Astrophysics</center> \n <hr> \n\n### [Death by Dark Matter](http://arxiv.org/abs/1907.06674v2) (1907.06674v2)\n<i>Jagjit Singh Sidhu, Robert J Scherrer, Glenn Starkman</b>\n\n<h10>2019-07-15</h10>\n> Macroscopic dark matter refers to a variety of dark matter candidates that would be expected to (elastically) scatter off of ordinary matter with a large geometric cross-section. A wide range of macro masses ![](http://latex2png.com/output//latex_68ced1eb95810d385dabc9cddd66e64f.png) and cross-sections ![](http://latex2png.com/output//latex_0901868ab589a1b9a3787cca4a3037a2.png) remain unprobed. We show that over a wide region within the unexplored parameter space, collisions of a macro with a human body would result in serious injury or death. We use the absence of such unexplained impacts with a well-monitored subset of the human population to exclude a region bounded by ![](http://latex2png.com/output//latex_732773455ebc7b557b6e43220584822e.png) cm![](http://latex2png.com/output//latex_c325d54e893a48d5fd764007d924c553.png) and ![](http://latex2png.com/output//latex_09bf0583ab443f87be42bda3077e03fb.png) kg. Our results open a new window on dark matter: the human body as a dark matter detector.\n\n### [Early Structure Formation in ![](http://latex2png.com/output//latex_57ab36b2298729499dff5ca89c1efe4e.png)PBH Cosmologies](http://arxiv.org/abs/1907.08129v1) (1907.08129v1)\n<i>Derek Inman, Yacine Ali-Haïmoud</b>\n\n<h10>2019-07-18</h10>\n> Cold dark matter (CDM) could be composed of primordial black holes (PBH) in addition to or instead of more orthodox weakly interacting massive particle dark matter (PDM). We study the formation of the first structures in such ![](http://latex2png.com/output//latex_2c5a069424a79c8fac46c445901441e6.png)PBH cosmologies using ![](http://latex2png.com/output//latex_b9e69f0f03051ff98f89be64ae45918f.png)-body simulations evolved from deep in the radiation era to redshift 99. When PBH are only a small component of the CDM, they are clothed by PDM to form isolated halos. On the other hand, when PBH make most of the CDM, halos can also grow via clustering of many PBH. We find that the halo mass function is well modelled via Poisson statistics assuming random initial conditions. We quantify the nonlinear velocities induced by structure formation and find that they are too small to significantly impact CMB constraints. A chief challenge is how best to extrapolate our results to lower redshifts relevant for some observational constraints.\n\n### [Estimates of Fast Radio Burst Dispersion Measures from Cosmological  Simulations](http://arxiv.org/abs/1903.07630v2) (1903.07630v2)\n<i>N. Pol, M. T. Lam, M. A. McLaughlin, T. J. W. Lazio, J. M. Cordes</b>\n\n<h10>2019-03-18</h10>\n> We calculate the dispersion measure (DM) contributed by the intergalactic medium (IGM) to the total measured DM for fast radio bursts (FRBs). We use the MareNostrum Instituto de Ciencias del Espacio (MICE) Onion Universe simulation (Fosalba et al. 2008) to track the evolution of the dark matter particle density over a large range of redshifts. We convert this dark matter particle number density to the corresponding free electron density and then integrate it to find the DM as a function of redshift. This approach yields an intergalactic DM of ![](http://latex2png.com/output//latex_e73f3093ae5a2ff9c166e258e3bc7e76.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png), with the large errors representative of the structure in the IGM. We place limits on the redshifts of the current population of observed FRBs. We also use our results to estimate the host galaxy contribution to the DM for the first repeater, FRB 121102, and show that the most probable host galaxy DM contribution, ![](http://latex2png.com/output//latex_742de1d03fb5145d3fa6f2011bb1a463.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png), is consistent with the estimate made using the Balmer emission lines in the spectrum of the host galaxy, ![](http://latex2png.com/output//latex_77fdfb1b5106b7ba25a5e971283eb17e.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png) (Tendulkar et al. 2017). We also compare our predictions for the host galaxy contribution to the DM for the observations of FRB 180924 (Bannister et al. 2019) and FRB 190523 (Ravi et al. 2019), both of which have been localized to a host galaxy.\n\n### [Many-field Inflation: Universality or Prior Dependence?](http://arxiv.org/abs/1907.08095v1) (1907.08095v1)\n<i>Perseas Christodoulidis, Diederik Roest, Robert Rosati</b>\n\n<h10>2019-07-18</h10>\n> We investigate the observational signatures of many-field inflation and present analytic expressions for the spectral index as a function of the prior. For a given prior we employ the central limit theorem and the horizon crossing approximation to derive universal predictions, as found previously. However, we also find a specific dependence on the prior choice for initial conditions that has not been seen in previous studies. Our main focus is on quadratic inflation, for which the initial conditions statistics decouple from those of the mass distribution, while other monomials are also briefly discussed. We verify the validity of our calculations by comparing to full numerical simulations with ![](http://latex2png.com/output//latex_7e24dea1023c6600ef254be2b9cb6565.png) fields using the transport method.\n\n### [The galaxy bias at second order in general relativity with Non-Gaussian  initial conditions](http://arxiv.org/abs/1907.08094v1) (1907.08094v1)\n<i>Obinna Umeh, Kazuya Koyama</b>\n\n<h10>2019-07-18</h10>\n> We present a systematic study of galaxy bias in the presence of primordial non-Gaussianity in General Relativity (GR) at second order in perturbation theory. The non-linearity of the Poisson equation in GR and primordial non-Gaussianity are consistently included. We show that the inclusion of non-local primordial non-Gaussianity in addition to local non-Gaussianity is important to show the absence of the modulation of small scale clustering by the long-wavelength mode in the single field slow-roll inflation. We study the bispectrum of the relativistic galaxy density in several gauges and identify the effect of primordial non-Gaussianity and GR corrections.\n\n# <center>High Energy Astrophysical Phenomena</center> \n <hr> \n\n### [Inverse Compton emission from millisecond pulsars in the Galactic bulge](http://arxiv.org/abs/1901.07025v2) (1901.07025v2)\n<i>Deheng Song, Oscar Macias, Shunsaku Horiuchi</b>\n\n<h10>2019-01-21</h10>\n> Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly ![](http://latex2png.com/output//latex_174ac781ee40ce7c1db4f55851bbbc24.png)20 degrees in latitude. The leading theory postulates that this GeV excess is the aggregate emission from a large number of faint millisecond pulsars (MSPs). The electrons and positrons (![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png)) injected by this population could produce detectable inverse-Compton (IC) emissions by up-scattering ambient photons to gamma-ray energies. In this work, we calculate such IC emissions using GALPROP. A triaxial three-dimensional model of the bulge stars obtained from a fit to infrared data is used as a tracer of the putative MSP population. This model is compared against one in which the MSPs are spatially distributed as a Navarro-Frenk-White squared profile. We show that the resulting spectra for both models are indistinguishable, but that their spatial morphologies have salient recognizable features. The IC component above ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)TeV energies carries information on the spatial morphology of the injected ![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png). Such differences could potentially be used by future high-energy gamma-ray detectors such as the Cherenkov Telescope Array to provide a viable multiwavelength handle for the MSP origin of the GeV excess.\n\n### [Testing cosmology and fundamental physics with the Cherenkov Telescope  Array](http://arxiv.org/abs/1907.08141v1) (1907.08141v1)\n<i>H. Martínez-Huerta, J. Biteau, J. Lefaucheur, M. Meyer, S. Pita, I. Vovk</b>\n\n<h10>2019-07-18</h10>\n> The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray astronomy at energies above 30 GeV. Thanks to its unique capabilities, CTA observations will address a plethora of open questions in astrophysics ranging from the origin of cosmic messengers to the exploration of the frontiers of physics. In this note, we present a comprehensive sensitivity study to assess the potential of CTA to measure the ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray absorption on the extragalactic background light (EBL), to constrain or detect intergalactic magnetic fields (IGMFs), and probe physics beyond the Standard Model such as axion-like particles (ALPs) and Lorentz invariance violation (LIV), which could modify the ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray spectra features expected from EBL absorption. Our results suggest that CTA will have unprecedented sensitivity to detect IGMF signatures and will probe so-far unexplored regions of the LIV and ALP parameter space. Furthermore, an indirect measurement of the EBL and of its evolution will be performed with unrivaled precision.\n\n### [Segregation of Stellar-Mass Black Holes at the Galactic Center](http://arxiv.org/abs/1903.02578v3) (1903.02578v3)\n<i>Razieh Emami, Abraham Loeb</b>\n\n<h10>2019-03-06</h10>\n> We simulate the star cluster near the center of the Milky Way galaxy. Using the Fokker Planck approach we consider the time evolution of the density profile of stars and stellar mass black holes (BHs) for various initial profiles. BHs sink toward the center of the galaxy where they are swallowed by SgrA*. We show that the mass loss increases the mass of SgrA* by up to 20\\% for shallow initial radial profile with a power-law slope ![](http://latex2png.com/output//latex_764f39554b8e1a76b3e33973b7724bfc.png), and BH mass of ![](http://latex2png.com/output//latex_502b3c5b8372d6cb98bc1c5b907a8ca9.png). We model the consumption rate analytically and compare it with the results from simulation. Stars make the main contribution in increasing the mass of SgrA*. We show the growth of Bahcall-Wolf cusp in the density profile of BHs in agreement with direct N-body simulations.\n\n### [EmCa -- Electromagnetic-Cascades Simulation Package](http://arxiv.org/abs/1907.06924v2) (1907.06924v2)\n<i>Stephan Meighen-Berger, Anatoli Fedynitch, Matthias Huber</b>\n\n<h10>2019-07-16</h10>\n> Electromagnetic-Cascades (EmCa) is a Python package for the simulation of electromagnetic cascades in various materials. The showers are modeled using cascade equations and the relevant interactions, specifically pair production, Bremsstrahlung, Compton scattering and ionization. This methodology has the advantage of being computationally inexpensive and fast, unlike Monte Carlo methods. The code includes low and high energy material effects, allowing for a high range of validity of the simulation results. EmCa is easily extendable and offers a framework for testing different electromagnetic interaction models. In combination with MCEq, a Python package for hadronic particle showers using cascade equations, full simulations of atmospheric fluxes can be done.\n\n### [On the role of a cavity in the hypernova ejecta of GRB 190114C](http://arxiv.org/abs/1904.03163v4) (1904.03163v4)\n<i>R. Ruffini, J. D. Melon Fuksman, G. V. Vereshchagin</b>\n\n<h10>2019-04-05</h10>\n> Within the binary-driven hypernova I (BdHN I) scenario, the gamma-ray burst GRB190114C originates in a binary system composed of a massive carbon-oxygen core (CO![](http://latex2png.com/output//latex_6388b98e96a6dfb3adefe93eda59d45b.png)), and a binary neutron star (NS) companion. As the CO![](http://latex2png.com/output//latex_6388b98e96a6dfb3adefe93eda59d45b.png) undergoes a supernova explosion with the creation of a new neutron star (![](http://latex2png.com/output//latex_9572b94ee9291e7516491a08be107c07.png)NS), hypercritical accretion occurs onto the companion binary neutron star until it exceeds the critical mass for gravitational collapse. The formation of a black hole (BH) captures ![](http://latex2png.com/output//latex_44ed32f3bcc25c4ff8fc4e6346d446f3.png) baryons by enclosing them within its horizon, and thus a cavity of approximately ![](http://latex2png.com/output//latex_009105d3d731bc5075d6e324e6038219.png) cm is formed around it with initial density ![](http://latex2png.com/output//latex_f73fc73ec416f3faa0db4eb4472146df.png) g/cm![](http://latex2png.com/output//latex_3ab3261c243a6faefe22e74991dd6a96.png). A further depletion of baryons in the cavity originates from the expansion of the electron-positron-photon (![](http://latex2png.com/output//latex_9db91924f36f28e53a35fa1861cd46fb.png)) plasma formed at the collapse, reaching a density of ![](http://latex2png.com/output//latex_aac545525cd9c01cc76ed6bdd18c3c17.png) g/cm![](http://latex2png.com/output//latex_3ab3261c243a6faefe22e74991dd6a96.png) by the end of the interaction. It is demonstrated here using an analytical model complemented by a hydrodynamical numerical simulation that part of the ![](http://latex2png.com/output//latex_9db91924f36f28e53a35fa1861cd46fb.png) plasma is reflected off the walls of the cavity. The consequent outflow and its observed properties are shown to coincide with the featureless emission occurring in a time interval of duration ![](http://latex2png.com/output//latex_ee4a90454f1c12aa24fc95cca7d04488.png), measured in the rest frame of the source, between ![](http://latex2png.com/output//latex_57d2108e8bf558e5f85fd008628366f0.png) and ![](http://latex2png.com/output//latex_d820690da3b699516cff01eec847a032.png) s of the GBM observation. Moreover, similar features of the GRB light curve were previously observed in GRB 090926A and GRB 130427A, all belonging to the BdHN I class. This interpretation supports the general conceptual framework presented in Ruffini et al. (2019) and guarantees that a low baryon density is reached in the cavity, a necessary condition for the operation of the \"inner engine\" of the GRB presented in an accompanying article (Ruffini & Moradi 2019).\n\n# <center>Instrumentation And Methods In Astrophysics</center> \n <hr> \n\n### [Comparing Multi-class, Binary and Hierarchical Machine Learning  Classification schemes for variable stars](http://arxiv.org/abs/1907.08189v1) (1907.08189v1)\n<i>Zafiirah Hosenie, Robert Lyon, Benjamin Stappers, Arrykrishna Mootoovaloo</b>\n\n<h10>2019-07-18</h10>\n> Upcoming synoptic surveys are set to generate an unprecedented amount of data. This requires an automatic framework that can quickly and efficiently provide classification labels for several new object classification challenges. Using data describing 11 types of variable stars from the Catalina Real-Time Transient Surveys (CRTS), we illustrate how to capture the most important information from computed features and describe detailed methods of how to robustly use Information Theory for feature selection and evaluation. We apply three Machine Learning (ML) algorithms and demonstrate how to optimize these classifiers via cross-validation techniques. For the CRTS dataset, we find that the Random Forest (RF) classifier performs best in terms of balanced-accuracy and geometric means. We demonstrate substantially improved classification results by converting the multi-class problem into a binary classification task, achieving a balanced-accuracy rate of ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)99 per cent for the classification of ![](http://latex2png.com/output//latex_9b6f06e27b3c0947f4156ccd5ed540d0.png)-Scuti and Anomalous Cepheids (ACEP). Additionally, we describe how classification performance can be improved via converting a 'flat-multi-class' problem into a hierarchical taxonomy. We develop a new hierarchical structure and propose a new set of classification features, enabling the accurate identification of subtypes of cepheids, RR Lyrae and eclipsing binary stars in CRTS data.\n\n### [Entering into the Wide Field Adaptive Optics Era in the Northern  Hemisphere](http://arxiv.org/abs/1907.08169v1) (1907.08169v1)\n<i>Gaetano Sivo, John Blakeslee, Jennifer Lotz, Henry Roe, Morten Andersen, Julia Scharwachter, David Palmer, Scot Kleinman, Andy Adamson, Paul Hirst, Eduardo Marin, Laure Catala, Marcos van Dam, Stephen Goodsell, Natalie Provost, Ruben Diaz, Inger Jorgensen, Hwihyun Kim, Marie Lemoine-Busserole, Celia Blain, Mark Chun, Mark Ammons, Julian Christou, Charlotte Bond, Suresh Sivanandam, Paolo Turri, Peter Wizinowich, Carlos Correia, Benoit Neichel, Jean-Pierre Veran, Simone Esposito, Masen Lamb, Thierry Fusco, Francois Rigaut, Eric Steinbring</b>\n\n<h10>2019-07-18</h10>\n> As part of the National Science Foundation funded \"Gemini in the Era of MultiMessenger Astronomy\" (GEMMA) program, Gemini Observatory is developing GNAO, a widefield adaptive optics (AO) facility for Gemini-North on Maunakea, the only 8m-class open-access telescope available to the US astronomers in the northern hemisphere. GNAO will provide the user community with a queue-operated Multi-Conjugate AO (MCAO) system, enabling a wide range of innovative solar system, Galactic, and extragalactic science with a particular focus on synergies with JWST in the area of time-domain astronomy. The GNAO effort builds on institutional investment and experience with the more limited block-scheduled Gemini Multi-Conjugate System (GeMS), commissioned at Gemini South in 2013. The project involves close partnerships with the community through the recently established Gemini AO Working Group and the GNAO Science Team, as well as external instrument teams. The modular design of GNAO will enable a planned upgrade to a Ground Layer AO (GLAO) mode when combined with an Adaptive Secondary Mirror (ASM). By enhancing the natural seeing by an expected factor of two, GLAO will vastly improve Gemini North's observing efficiency for seeing-limited instruments and strengthen its survey capabilities for multi-messenger astronomy.\n\n### [Laboratory rotational spectroscopy of isotopic acetone,  CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png), and astronomical search in  Sagittarius B2(N2)](http://arxiv.org/abs/1907.08073v1) (1907.08073v1)\n<i>Matthias H. Ordu, Oliver Zingsheim, Arnaud Belloche, Frank Lewen, Robin T. Garrod, Karl M. Menten, Stephan Schlemmer, Holger S. P. Müller</b>\n\n<h10>2019-07-18</h10>\n> We want to study the rotational spectra of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and search for them in Sagittarius B2(N2). We investigated the laboratory rotational spectrum of isotopically enriched CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) between 40 GHz and 910 GHz and of acetone between 36 GHz and 910 GHz in order to study ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in natural isotopic composition. In addition, we searched for emission lines produced by these species in a molecular line survey of Sagittarius B2(N) carried out with ALMA. Discrepancies between predictions of the main isotopic species and the ALMA spectrum prompted us to revisit the rotational spectrum of this isotopolog. We assigned 9711 new transitions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and 63 new transitions of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in the laboratory spectra. More than 1000 additional lines were assigned for the main isotopic species. We modeled the ground state data of all three isotopologs satisfactorily with the ERHAM program. We find that models of the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) improve only marginally. No transition of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) is clearly detected toward the hot molecular core Sgr B2(N2). However, we report a tentative detection of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) with a ![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)C/![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)C isotopic ratio of 27 that is consistent with the ratio previously measured for alcohols in this source. Several dozens of transitions of both torsional states of the main isotopolog are detected as well. Our predictions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) are reliable into the terahertz region. The spectrum of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) should be revisited in the laboratory with an enriched sample. Transitions pertaining to the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) could be identified unambiguously in Sagittarius B2(N2).\n\n### [Monte Carlo study of a single SST-1M prototype for the Cherenkov  Telescope Array](http://arxiv.org/abs/1907.08061v1) (1907.08061v1)\n<i>Jakub Jurysek, Imen Al Samarai, Cyril Alispach, Matteo Balbo, Anastasia Maria Barbano, Vasyl Beshley, Adrian Biland, Jiri Blazek, Jacek Błocki, Jerzy Borkowski, Tomek Bulik, Frank Raphael Cadoux, Ladislav Chytka, Victor Coco, Nicolas De Angelis, Domenico Della Volpe, Yannick Favre, Tomasz Gieras, Mira Grudzińska, Petr Hamal, Mathieu Heller, Miroslav Hrabovsky, Jerzy Kasperek, Katarzyna Koncewicz, Andrzej Kotarba, Etienne Lyard, Emil Mach, Dusan Mandat, Stanislav Michal, Jerzy Michalowski, Rafal Moderski, Teresa Montaruli, Andrii Nagai, Dominik Neise, Jacek Niemiec, Theodore Rodrigue Njoh Ekoume, Michal Ostrowski, Miroslav Palatka, Pawel Pasko, Miroslav Pech, Bartłomiej Pilszyk, Henry Przybilski, Pawel Rajda, Yves Renier, Paweł Rozwadowski, Petr Schovanek, K. Seweryn, Vitalii Sliusar, Dorota Smakulska, Dorota Sobczyńska, Łukasz Stawarz, Jacek Świerblewski, Paweł Świerk, Petr Travnicek, Isaac Troyano Pujadas, Roland Walter, Marek Wiecek, Aleksander Zagdański, Krzystof Zietara</b>\n\n<h10>2019-07-18</h10>\n> The SST-1M telescope was developed as a prototype of a Small-Size-Telescope for the Cherenkov Telescope Array observatory and it has been extensively tested in Krakow since 2017. In this contribution we present validation of the Monte Carlo model of the prototype and expected performance in Krakow conditions. We focus on gamma/hadron separation and mono reconstruction of energy and gamma photon arrival direction using Machine learning methods.\n\n### [Embedding Climate Change Engagement in Astronomy Education and Research](http://arxiv.org/abs/1907.08043v1) (1907.08043v1)\n<i>Kathryn Williamson, Travis A. Rector, James Lowenthal</b>\n\n<h10>2019-07-18</h10>\n> This White Paper is a call to action for astronomers to respond to climate change with a large structural transition within our profession. Many astronomers are deeply concerned about climate change and act upon it in their personal and professional lives, and many organizations within astronomy have incorporated incremental changes. We need a collective impact model to better network and grow our efforts so that we can achieve results that are on the scale appropriate to address climate change at the necessary level indicated by scientific research; e.g., becoming carbon neutral by 2050. We need to implement strategies within two primary drivers of our field: (1) Education and Outreach, and (2) Research Practices and Infrastructure. (1) In the classroom and through public talks, astronomers reach a large audience. Astronomy is closely connected to the science of climate change, and it is arguably the most important topic we include in our curriculum. Due to misinformation and disinformation, climate change communication is different than for other areas of science. We therefore need to expand our communication and implement effective strategies, for which there is now a considerable body of research. (2) On a per-person basis astronomers have an outsized carbon impact. There are numerous ways we can reduce our footprint; e.g., in the design and operation of telescope facilities and in the optimization and reduction of travel. Fortunately, many of these solutions are win-win scenarios, e.g., increasing the online presence of conferences will reduce the carbon footprint while increasing participation, especially for astronomers working with fewer financial resources. Astronomers have an obligation to act on climate change in every way possible, and we need to do it now. In this White Paper, we outline a plan for collective impact using a Networked Improvement Community (NIC) approach.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics A |2019-07-21",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Astrophysics Of Galaxies</center> \n <hr> \n\n### [Inverse Compton emission from millisecond pulsars in the Galactic bulge](http://arxiv.org/abs/1901.07025v2) (1901.07025v2)\n<i>Deheng Song, Oscar Macias, Shunsaku Horiuchi</b>\n\n<h10>2019-01-21</h10>\n> Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly ![](http://latex2png.com/output//latex_174ac781ee40ce7c1db4f55851bbbc24.png)20 degrees in latitude. The leading theory postulates that this GeV excess is the aggregate emission from a large number of faint millisecond pulsars (MSPs). The electrons and positrons (![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png)) injected by this population could produce detectable inverse-Compton (IC) emissions by up-scattering ambient photons to gamma-ray energies. In this work, we calculate such IC emissions using GALPROP. A triaxial three-dimensional model of the bulge stars obtained from a fit to infrared data is used as a tracer of the putative MSP population. This model is compared against one in which the MSPs are spatially distributed as a Navarro-Frenk-White squared profile. We show that the resulting spectra for both models are indistinguishable, but that their spatial morphologies have salient recognizable features. The IC component above ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)TeV energies carries information on the spatial morphology of the injected ![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png). Such differences could potentially be used by future high-energy gamma-ray detectors such as the Cherenkov Telescope Array to provide a viable multiwavelength handle for the MSP origin of the GeV excess.\n\n### [Stellar and Dust Properties of a Complete Sample of Massive Dusty  Galaxies at ![](http://latex2png.com/output//latex_687d102cde5d9447a12d61c03b445e2a.png) from MAGPHYS Modeling of UltraVISTA DR3 and  Herschel Photometry](http://arxiv.org/abs/1907.08152v1) (1907.08152v1)\n<i>Nicholas S. Martis, Danilo M. Marchesini, Adam Muzzin, Mauro Stefanon, Gabriel Brammer, Elisabete da Cunha, Anna Sajina, Ivo Labbé</b>\n\n<h10>2019-07-18</h10>\n> We investigate the stellar and dust properties of massive (log![](http://latex2png.com/output//latex_36d6933ef3a1d279d7818f2897efbc64.png)) and dusty (![](http://latex2png.com/output//latex_a7602de34833e2deb98212db0e22a84a.png)) galaxies at ![](http://latex2png.com/output//latex_687d102cde5d9447a12d61c03b445e2a.png) by modeling their spectral energy distributions (SEDs) obtained from the combination of UltraVISTA DR3 photometry and \\textit{Herschel} PACS-SPIRE data using MAGPHYS. Although the rest-frame U-V vs V-J (UVJ) diagram traces well the star-formation rates (SFR) and dust obscuration (A![](http://latex2png.com/output//latex_48090e970ef5d526b553fe46671433d1.png)) out to ![](http://latex2png.com/output//latex_ce49f761a8620c968ffa75e0d2bfc096.png), ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)15-20\\% of the sample surprisingly resides in the quiescent region of the UVJ diagram, while ![](http://latex2png.com/output//latex_621ae1f65fc3f860567f1b758c86286b.png)\\% at ![](http://latex2png.com/output//latex_8fbbf165b26a10d18d10d079718d076d.png) fall in the unobscured star-forming region. The median SED of massive dusty galaxies exhibits weaker MIR and UV emission, and redder UV slopes with increasing cosmic time. The IR emission for our sample has a significant contribution (![](http://latex2png.com/output//latex_075568e24fa817c1e10dd3f585396878.png)) from dust heated by evolved stellar populations rather than star formation, demonstrating the need for panchromatic SED modeling. The local relation between dust mass and SFR is followed only by a sub-sample with cooler dust temperatures, while warmer objects have reduced dust masses at a given SFR. Most star-forming galaxies in our sample do not follow local IRX-![](http://latex2png.com/output//latex_a09ff5aa4faa8ac1a92a3e088b122835.png) relations, though IRX does strongly correlate with A![](http://latex2png.com/output//latex_48090e970ef5d526b553fe46671433d1.png). Our sample follows local relations, albeit with large scatter, between ISM diagnostics and sSFR. We show that FIR-detected sources represent the extreme of a continuous population of dusty galaxies rather than a fundamentally different population. Finally, using commonly adopted relations to derive SFRs from the combination of the rest-frame UV and the observed 24![](http://latex2png.com/output//latex_d6ab24fcd975e3392b48ba13cd4778fc.png)m is found to overestimate the SFR by a factor of 3-5 for the galaxies in our sample.\n\n### [Segregation of Stellar-Mass Black Holes at the Galactic Center](http://arxiv.org/abs/1903.02578v3) (1903.02578v3)\n<i>Razieh Emami, Abraham Loeb</b>\n\n<h10>2019-03-06</h10>\n> We simulate the star cluster near the center of the Milky Way galaxy. Using the Fokker Planck approach we consider the time evolution of the density profile of stars and stellar mass black holes (BHs) for various initial profiles. BHs sink toward the center of the galaxy where they are swallowed by SgrA*. We show that the mass loss increases the mass of SgrA* by up to 20\\% for shallow initial radial profile with a power-law slope ![](http://latex2png.com/output//latex_764f39554b8e1a76b3e33973b7724bfc.png), and BH mass of ![](http://latex2png.com/output//latex_502b3c5b8372d6cb98bc1c5b907a8ca9.png). We model the consumption rate analytically and compare it with the results from simulation. Stars make the main contribution in increasing the mass of SgrA*. We show the growth of Bahcall-Wolf cusp in the density profile of BHs in agreement with direct N-body simulations.\n\n### [Signatures of diffuse interstellar gas in the Galaxy Evolution Explorer  all sky survey](http://arxiv.org/abs/1907.08099v1) (1907.08099v1)\n<i>Marcelo Armengot, Ana I. Gomez de Castro</b>\n\n<h10>2019-07-18</h10>\n> The all sky survey run by the Galaxy Evolution Explorer (GALEX AIS) mapped about 85\\% of the Galaxy at ultraviolet (UV) wavelengths and detected the diffuse UV background produced by the scattering of the radiation from OBA stars by interstellar dust grains. Against this background, diffuse weak structures are detected as well as the UV counterparts to nebulae and molecular clouds. To make full profit of the survey, unsupervised and semi-supervised procedures need to be implemented. The main objective of this work is to implement and analyze the results of the method developed by us for the blind detection of ISM features in the GALEX AIS . Most ISM features are detected at very low signal levels (dark filaments, globules) against the already faint UV background. We have defined an index, the UV background fluctuations index (or UBF index), to identify areas of the sky where these fluctuations are detected. The algorithm is applied to the images obtained in the FUV 1344 -- 1786 Angstroms) band since this is less polluted by stellar sources, facilitating the automated detection. The UBF index is shown to be sensitive to the main star forming regions within the Gould's Belt, as well as to some prominent loops like Loop I or the Eridanus and Monogem areas. The catalogue with the UBF index values is made available on-line to the community.\n\n### [Laboratory rotational spectroscopy of isotopic acetone,  CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png), and astronomical search in  Sagittarius B2(N2)](http://arxiv.org/abs/1907.08073v1) (1907.08073v1)\n<i>Matthias H. Ordu, Oliver Zingsheim, Arnaud Belloche, Frank Lewen, Robin T. Garrod, Karl M. Menten, Stephan Schlemmer, Holger S. P. Müller</b>\n\n<h10>2019-07-18</h10>\n> We want to study the rotational spectra of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and search for them in Sagittarius B2(N2). We investigated the laboratory rotational spectrum of isotopically enriched CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) between 40 GHz and 910 GHz and of acetone between 36 GHz and 910 GHz in order to study ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in natural isotopic composition. In addition, we searched for emission lines produced by these species in a molecular line survey of Sagittarius B2(N) carried out with ALMA. Discrepancies between predictions of the main isotopic species and the ALMA spectrum prompted us to revisit the rotational spectrum of this isotopolog. We assigned 9711 new transitions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and 63 new transitions of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in the laboratory spectra. More than 1000 additional lines were assigned for the main isotopic species. We modeled the ground state data of all three isotopologs satisfactorily with the ERHAM program. We find that models of the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) improve only marginally. No transition of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) is clearly detected toward the hot molecular core Sgr B2(N2). However, we report a tentative detection of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) with a ![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)C/![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)C isotopic ratio of 27 that is consistent with the ratio previously measured for alcohols in this source. Several dozens of transitions of both torsional states of the main isotopolog are detected as well. Our predictions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) are reliable into the terahertz region. The spectrum of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) should be revisited in the laboratory with an enriched sample. Transitions pertaining to the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) could be identified unambiguously in Sagittarius B2(N2).\n\n# <center>Earth And Planetary Astrophysics</center> \n <hr> \n\n### [Martian Year 34 Column Dust Climatology from Mars Climate Sounder  Observations: Reconstructed Maps and Model Simulations](http://arxiv.org/abs/1907.08187v1) (1907.08187v1)\n<i>Luca Montabone, Aymeric Spiga, David M. Kass, Armin Kleinböhl, François Forget, Ehouarn Millour</b>\n\n<h10>2019-07-18</h10>\n> We have reconstructed longitude-latitude maps of column dust optical depth (CDOD) for Martian year (MY) 34 (May 5, 2017 --- March 23, 2019) using observations by the Mars Climate Sounder (MCS) aboard NASA's Mars Reconnaissance Orbiter spacecraft. Our methodology works by gridding standard and newly available estimates of CDOD from MCS limb observations, using the \"iterative weighted binning\" methodology. In this work, we reconstruct four gridded CDOD maps per sol, at different Mars Universal Times. Together with the seasonal and day-to-day variability, the use of several maps per sol allows to explore also the daily variability of CDOD in the MCS dataset, which is shown to be particularly strong during the MY 34 equinoctial Global Dust Event (GDE). Regular maps of CDOD are then produced by daily averaging and spatially interpolating the irregularly gridded maps using a standard \"kriging\" interpolator, and can be used as \"dust scenario\" for numerical model simulations. In order to understand whether the daily variability of CDOD has a physical explanation, we have carried out numerical simulations with the \"Laboratoire de M\\'et\\'eorologie Dynamique\" Mars Global Climate Model. Using a \"free dust\" run initiated at ![](http://latex2png.com/output//latex_cb747fcfb5a7c79cb2bce2a95fffbae0.png) with the corresponding kriged map, but subsequently free of further CDOD forcing, we show that the model is able to account for some of the observed daily variability in CDOD. The model serves also to confirm that the use of the MY 34 daily-averaged dust scenario in a GCM produces results consistent with those obtained for the MY 25 GDE.\n\n### [Parametric study of polar configurations around binaries](http://arxiv.org/abs/1907.08180v1) (1907.08180v1)\n<i>Cristian Giuppone, Nicolás Cuello</b>\n\n<h10>2019-07-18</h10>\n> Dynamical studies suggest that most of the circumbinary discs (CBDs) should be coplanar. However, under certain initial conditions, the CBD can evolve toward polar orientation. Here we extend the parametric study of polar configurations around detached close-in binaries through ![](http://latex2png.com/output//latex_b9e69f0f03051ff98f89be64ae45918f.png)-body simulations. For polar configurations around binaries with mass ratios ![](http://latex2png.com/output//latex_8252603f68bd2a6b7e714e5055bdac3d.png) below ![](http://latex2png.com/output//latex_c174e69b59fb25a86e3f276774fcfc6f.png), the nominal location of the mean motion resonance (MMR) ![](http://latex2png.com/output//latex_403228beb8df83fca1ede3b87e641313.png) predicts the limit of stability for ![](http://latex2png.com/output//latex_4b022dd92ae67442ac01e19b96a74083.png). Alternatively, for ![](http://latex2png.com/output//latex_3d2dd7ecb84849ef6cadcbcb4bc8ef76.png) or ![](http://latex2png.com/output//latex_45508835633b63f8e8a286d5d26dd555.png), the nominal location of the MMR ![](http://latex2png.com/output//latex_baceaca3abc651537dff6e5075f8a35c.png) is the closest stable region. The presence of a} giant planet increases the region of forbidden polar configurations around low mass ratio binaries with eccentricities ![](http://latex2png.com/output//latex_feb072c4f98da11bdc2850e676bd106d.png) with respect to rocky earth-like planets. For equal mass stars, the eccentricity excitation ![](http://latex2png.com/output//latex_6331d6100b52a4af90d24c003741a702.png) of polar orbits smoothly increases with decreasing distance to the binary. For ![](http://latex2png.com/output//latex_079d841a67b4e71c51e7b105df062512.png), ![](http://latex2png.com/output//latex_6331d6100b52a4af90d24c003741a702.png) can reach values as high as ![](http://latex2png.com/output//latex_ab7c1933e38fc63e865a89d38a75641e.png). Finally, we studied polar configurations around ![](http://latex2png.com/output//latex_a91a77936d0f58bf2860a8664c55f92a.png) and show that the region of stability is strongly affected by the relative positions of the nodes. The most stable configurations in the system correspond to polar particles, which are not expected to survive on longer time-scales due to the presence of the external perturber HD~![](http://latex2png.com/output//latex_5074a8fb06751561a86123638b647ec9.png).\n\n### [Geochemistry constrains global hydrology on Early Mars](http://arxiv.org/abs/1907.08166v1) (1907.08166v1)\n<i>Edwin S. Kite, Mohit Melwani Daswani</b>\n\n<h10>2019-07-18</h10>\n> Ancient hydrology is recorded by sedimentary rocks on Mars. The most voluminous sedimentary rocks that formed during Mars' Hesperian period are sulfate-rich rocks, explored by the ![](http://latex2png.com/output//latex_1a261583ce2a8cd37288ba32b4c2fc8d.png) rover from 2004-2012 and soon to be investigated by the ![](http://latex2png.com/output//latex_6d132474afc6a522c3ebe2fded21235e.png) rover at Gale crater. A leading hypothesis for the origin of these sulfates is that the cations were derived from evaporation of deep-sourced groundwater, as part of a global circulation of groundwater. Global groundwater circulation would imply sustained warm Earthlike conditions on Early Mars. Global circulation of groundwater including infiltration of water initially in equilibrium with Mars' CO![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) atmosphere implies subsurface formation of carbonate. We find that the CO![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) sequestration implied by the global groundwater hypothesis for the origin of sulfate-rich rocks on Mars is 30-5000 bars if the ![](http://latex2png.com/output//latex_1a261583ce2a8cd37288ba32b4c2fc8d.png) data are representative of Hesperian sulfate-rich rocks, which is so large that (even accounting for volcanic outgassing) it would bury the atmosphere. This disfavors the hypothesis that the cations for Mars' Hesperian sulfates were derived from upwelling of deep sourced groundwater. If, instead, Hesperian sulfate-rich rocks are approximated as pure Mg-sulfate (no Fe), then the CO![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) sequestration is 0.3-400 bars. The low end of this range is consistent with the hypothesis that the cations for Mars' Hesperian sulfates were derived from upwelling of deep sourced groundwater. In both cases, carbon sequestration by global groundwater circulation actively works to terminate surface habitability, rather than being a passive marker of warm Earthlike conditions. ![](http://latex2png.com/output//latex_6d132474afc6a522c3ebe2fded21235e.png) will soon be in a position to discriminate between these two hypotheses. Our work links Mars sulfate cation composition, carbon isotopes, and climate change.\n\n### [The multiplicity distribution of Kepler's exoplanets](http://arxiv.org/abs/1907.08148v1) (1907.08148v1)\n<i>Emily Sandford, David Kipping, Michael Collins</b>\n\n<h10>2019-07-18</h10>\n> The true multiplicity distribution of transiting planet systems is obscured by strong observational biases, leading low-multiplicity systems to be overrepresented in the observed sample. Using the Kepler FGK planet hosts, we employ approximate Bayesian computation to infer the multiplicity distribution by comparing simulated catalogs to the observed one. After comparing a total of ten different multiplicity distributions, half of which were two-population models, to the observed data, we find that a single-population model following a Zipfian distribution is able to explain the Kepler data as well as any of the dichotomous models we test. Our work provides another example of a way to explain the observed Kepler multiplicities without invoking a dichotomous planet population. Using our preferred Zipfian model, we estimate that an additional ![](http://latex2png.com/output//latex_ff9f96cee7fbd1b8518786e9ccba8529.png) planets likely reside in the 1537 FGK Kepler systems studied in this work, which would increase the planet count by a factor of ![](http://latex2png.com/output//latex_648663d43d776586082481e7de8bc851.png). Of these hidden worlds, ![](http://latex2png.com/output//latex_3d14ebbdb47afb29e0c0db4f8f057300.png) are expected to reside in ostensibly single-transiting-planet systems, meaning that an additional planet(s) is expected for approximately 1-in-2 such Kepler systems.\n\n### [Observational constraints on dust disk sizes in tidally truncated  protoplanetary disks in multiple systems in the Taurus region](http://arxiv.org/abs/1907.03846v3) (1907.03846v3)\n<i>C. F. Manara, M. Tazzari, F. Long, G. J. Herczeg, G. Lodato, A. A. Rota, P. Cazzoletti, G. van der Plas, P. Pinilla, G. Dipierro, S. Edwards, D. Harsono, D. Johnstone, Y. Liu, F. Menard, B. Nisini, E. Ragusa, Y. Boehler, S. Cabrit</b>\n\n<h10>2019-07-08</h10>\n> The impact of stellar multiplicity on the evolution of planet-forming disks is still the subject of debate. Here we present and analyze disk structures around ten multiple stellar systems that were included in an unbiased, high spatial resolution survey performed with ALMA of 32 protoplanetary disks in the Taurus star-forming region. At the unprecedented spatial resolution of ~0.12\" we detect and spatially resolve the disks around all primary stars, and those around eight secondary and one tertiary star. The dust radii of disks around multiple stellar systems are smaller than those around single stars in the same stellar mass range and in the same region. The disks in multiple stellar systems also show a steeper decay of the millimeter continuum emission at the outer radius than disks around single stars, suggestive of the impact of tidal truncation on the shape of the disks in multiple systems. However, the observed ratio between the dust disk radii and the observed separation of the stars in the multiple systems is consistent with analytic predictions of the effect of tidal truncation only if the eccentricities of the binaries are rather high (typically >0.5), or if the observed dust radii are a factor of two smaller than the gas radii, as is typical for isolated systems. Similar high-resolution studies targeting the gaseous emission from disks in multiple stellar systems are required to resolve this question.\n\n# <center>Solar And Stellar Astrophysics</center> \n <hr> \n\n### [Formation of quasi-periodic slow magnetoacoustic wave trains by the  heating/cooling misbalance](http://arxiv.org/abs/1907.08168v1) (1907.08168v1)\n<i>D. I. Zavershinskii, D. Y. Kolotkov, V. M. Nakariakov, N. E. Molevich, D. S. Ryashchikov</b>\n\n<h10>2019-07-18</h10>\n> Slow magnetoacoustic waves are omnipresent in both natural and laboratory plasma systems. The wave-induced misbalance between plasma cooling and heating processes causes the amplification or attenuation, and also dispersion, of slow magnetoacoustic waves. The wave dispersion could be attributed to the presence of characteristic time scales in the system, connected with the plasma heating or cooling due to the competition of the heating and cooling processes in the vicinity of the thermal equilibrium. We analysed linear slow magnetoacoustic waves in a plasma in a thermal equilibrium formed by a balance of optically thin radiative losses, field-align thermal conduction, and an unspecified heating. The dispersion is manifested by the dependence of the effective adiabatic index of the wave on the wave frequency, making the phase and group speeds frequency-dependent. The mutual effect of the wave amplification and dispersion is shown to result into the occurrence of an oscillatory pattern in an initially broadband slow wave, with the characteristic period determined by the thermal misbalance time scales, i.e. by the derivatives of the combined radiation loss and heating function with respect to the density and temperature, evaluated at the equilibrium. This effect is illustrated by estimating the characteristic period of the oscillatory pattern, appearing because of thermal misbalance in the plasma of the solar corona. It is found that by an order of magnitude the period is about the typical periods of slow magnetoacoustic oscillations detected in the corona.\n\n### [Rigidly rotating, incompressible spheroid-ring systems: new  bifurcations, critical rotations and degenerate states](http://arxiv.org/abs/1907.08151v1) (1907.08151v1)\n<i>B. Basillais, J. -M. Huré</b>\n\n<h10>2019-07-18</h10>\n> The equilibrium of incompressible spheroid-ring systems in rigid rotation is investigated by numerical means for a unity density contrast. A great diversity of binary configurations is obtained, with no limit neither in the mass ratio, nor in the orbital separation. We found only detached binaries, meaning that the end-point of the ![](http://latex2png.com/output//latex_4383d7038c11cbc2515d0d3c1a530eb6.png)-sequence is the single binary state in strict contact, easily prone to mass-exchange. The solutions show a remarkable confinement in the rotation frequency-angular momentum diagram, with a total absence of equilibrium for ![](http://latex2png.com/output//latex_eac07c47f35f11702e14d9dd84258461.png). A short band of degeneracy is present next to the one-ring sequence. We unveil a continuum of bifurcations all along the ascending side of the Maclaurin sequence for eccentricities of the ellipsoid less than ![](http://latex2png.com/output//latex_3b05b022917e94bb7a101c56caf09ad1.png) and which involves a gradually expanding, initially massless loop.\n\n### [Observational constraints on dust disk sizes in tidally truncated  protoplanetary disks in multiple systems in the Taurus region](http://arxiv.org/abs/1907.03846v3) (1907.03846v3)\n<i>C. F. Manara, M. Tazzari, F. Long, G. J. Herczeg, G. Lodato, A. A. Rota, P. Cazzoletti, G. van der Plas, P. Pinilla, G. Dipierro, S. Edwards, D. Harsono, D. Johnstone, Y. Liu, F. Menard, B. Nisini, E. Ragusa, Y. Boehler, S. Cabrit</b>\n\n<h10>2019-07-08</h10>\n> The impact of stellar multiplicity on the evolution of planet-forming disks is still the subject of debate. Here we present and analyze disk structures around ten multiple stellar systems that were included in an unbiased, high spatial resolution survey performed with ALMA of 32 protoplanetary disks in the Taurus star-forming region. At the unprecedented spatial resolution of ~0.12\" we detect and spatially resolve the disks around all primary stars, and those around eight secondary and one tertiary star. The dust radii of disks around multiple stellar systems are smaller than those around single stars in the same stellar mass range and in the same region. The disks in multiple stellar systems also show a steeper decay of the millimeter continuum emission at the outer radius than disks around single stars, suggestive of the impact of tidal truncation on the shape of the disks in multiple systems. However, the observed ratio between the dust disk radii and the observed separation of the stars in the multiple systems is consistent with analytic predictions of the effect of tidal truncation only if the eccentricities of the binaries are rather high (typically >0.5), or if the observed dust radii are a factor of two smaller than the gas radii, as is typical for isolated systems. Similar high-resolution studies targeting the gaseous emission from disks in multiple stellar systems are required to resolve this question.\n\n### [First detections of H13CO+ and HC15N in the disk around HD 97048:  Evidence for a cold gas reservoir in the outer disk](http://arxiv.org/abs/1907.08060v1) (1907.08060v1)\n<i>Alice S. Booth, Catherine Walsh, John D. Ilee</b>\n\n<h10>2019-07-18</h10>\n> Observations of different molecular lines in protoplanetary disks provide valuable information on the gas kinematics, as well as constraints on the radial density and temperature structure of the gas. With ALMA we have detected H13CO+ (J=4-3) and HC15N (J=4-3) in the HD97048 protoplanetary disk for the first time. We compare these new detections to the ringed continuum mm-dust emission and the spatially resolved CO (J=3-2) and HCO+ (J=4-3) emission. The radial distributions of the H13CO+ and HC15N emission show hints of ringed sub-structure whereas, the optically thick tracers, CO and HCO+, do not. We calculate the HCO+/H13CO+ intensity ratio across the disk and find that it is radially constant (within our uncertainties). We use a physio-chemical parametric disk structure of the HD97048 disk with an analytical prescription for the HCO+ abundance distribution to generate synthetic observations of the HCO+ and H13CO+ disk emission assuming LTE. The best by-eye fit models require radial variations in the HCO+/H13CO+ abundance ratio and an overall enhancement in H13CO+ relative to HCO+. This highlights the need to consider isotope selective chemistry and in particular low temperature carbon isotope exchange reactions. This also points to the presence of a reservoir of cold molecular gas in the outer disk (T < 10K, R > 200au). Chemical models are required to confirm that isotope-selective chemistry alone can explain the observations presented here. With these data, we cannot rule out that the known dust substructure in the HD97048 disk is responsible for the observed trends in molecular line emission, and higher spatial resolution observations are required to fully explore the potential of optically thin tracers to probe planet-carved dust gaps. We also report non-detections of H13CO+ and HC15N in the HD100546 protoplanetary disk.\n\n### [The Tayler Instability in the Anelastic Approximation](http://arxiv.org/abs/1808.08958v2) (1808.08958v2)\n<i>J. Goldstein, R. H. D. Townsend, E. G. Zweibel</b>\n\n<h10>2018-08-27</h10>\n> The Tayler instability (TI) is a non-axisymmetric linear instability of an axisymmetric toroidal magnetic field in magneto-hydrostatic equilibrium (MHSE). Spruit (1999, 2002) has proposed that in a differentially rotating radiative region of a star, the TI drives a dynamo which generates magnetic fields that can efficiently transport angular momentum; a parameterized version of this dynamo has been implemented in stellar structure and evolution codes and shown to be important for determining interior spin. Numerical simulations, however, have yet to definitively demonstrate the operation of the dynamo. A criterion for the MHSE to develop the TI was derived using fully-compressible magneto-hydrodynamics, while numerical simulations of dynamical processes in stars frequently use an anelastic approximation. This motivates us to derive a new anelastic Tayler instability (anTI) criterion. We find that some MHSE configurations unstable in the fully-compressible case, become stable in the anelastic case. We find and characterize the unstable modes of a simple family of cylindrical MHSE configurations using numerical calculations, and discuss the implications for fully non-linear anelastic simulations.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics B |2019-07-20",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Cosmology And Nongalactic Astrophysics</center> \n <hr> \n\n### [Death by Dark Matter](http://arxiv.org/abs/1907.06674v2) (1907.06674v2)\n<i>Jagjit Singh Sidhu, Robert J Scherrer, Glenn Starkman</b>\n\n<h10>2019-07-15</h10>\n> Macroscopic dark matter refers to a variety of dark matter candidates that would be expected to (elastically) scatter off of ordinary matter with a large geometric cross-section. A wide range of macro masses ![](http://latex2png.com/output//latex_68ced1eb95810d385dabc9cddd66e64f.png) and cross-sections ![](http://latex2png.com/output//latex_0901868ab589a1b9a3787cca4a3037a2.png) remain unprobed. We show that over a wide region within the unexplored parameter space, collisions of a macro with a human body would result in serious injury or death. We use the absence of such unexplained impacts with a well-monitored subset of the human population to exclude a region bounded by ![](http://latex2png.com/output//latex_732773455ebc7b557b6e43220584822e.png) cm![](http://latex2png.com/output//latex_c325d54e893a48d5fd764007d924c553.png) and ![](http://latex2png.com/output//latex_09bf0583ab443f87be42bda3077e03fb.png) kg. Our results open a new window on dark matter: the human body as a dark matter detector.\n\n### [Early Structure Formation in ![](http://latex2png.com/output//latex_57ab36b2298729499dff5ca89c1efe4e.png)PBH Cosmologies](http://arxiv.org/abs/1907.08129v1) (1907.08129v1)\n<i>Derek Inman, Yacine Ali-Haïmoud</b>\n\n<h10>2019-07-18</h10>\n> Cold dark matter (CDM) could be composed of primordial black holes (PBH) in addition to or instead of more orthodox weakly interacting massive particle dark matter (PDM). We study the formation of the first structures in such ![](http://latex2png.com/output//latex_2c5a069424a79c8fac46c445901441e6.png)PBH cosmologies using ![](http://latex2png.com/output//latex_b9e69f0f03051ff98f89be64ae45918f.png)-body simulations evolved from deep in the radiation era to redshift 99. When PBH are only a small component of the CDM, they are clothed by PDM to form isolated halos. On the other hand, when PBH make most of the CDM, halos can also grow via clustering of many PBH. We find that the halo mass function is well modelled via Poisson statistics assuming random initial conditions. We quantify the nonlinear velocities induced by structure formation and find that they are too small to significantly impact CMB constraints. A chief challenge is how best to extrapolate our results to lower redshifts relevant for some observational constraints.\n\n### [Estimates of Fast Radio Burst Dispersion Measures from Cosmological  Simulations](http://arxiv.org/abs/1903.07630v2) (1903.07630v2)\n<i>N. Pol, M. T. Lam, M. A. McLaughlin, T. J. W. Lazio, J. M. Cordes</b>\n\n<h10>2019-03-18</h10>\n> We calculate the dispersion measure (DM) contributed by the intergalactic medium (IGM) to the total measured DM for fast radio bursts (FRBs). We use the MareNostrum Instituto de Ciencias del Espacio (MICE) Onion Universe simulation (Fosalba et al. 2008) to track the evolution of the dark matter particle density over a large range of redshifts. We convert this dark matter particle number density to the corresponding free electron density and then integrate it to find the DM as a function of redshift. This approach yields an intergalactic DM of ![](http://latex2png.com/output//latex_e73f3093ae5a2ff9c166e258e3bc7e76.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png), with the large errors representative of the structure in the IGM. We place limits on the redshifts of the current population of observed FRBs. We also use our results to estimate the host galaxy contribution to the DM for the first repeater, FRB 121102, and show that the most probable host galaxy DM contribution, ![](http://latex2png.com/output//latex_742de1d03fb5145d3fa6f2011bb1a463.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png), is consistent with the estimate made using the Balmer emission lines in the spectrum of the host galaxy, ![](http://latex2png.com/output//latex_77fdfb1b5106b7ba25a5e971283eb17e.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png) (Tendulkar et al. 2017). We also compare our predictions for the host galaxy contribution to the DM for the observations of FRB 180924 (Bannister et al. 2019) and FRB 190523 (Ravi et al. 2019), both of which have been localized to a host galaxy.\n\n### [Many-field Inflation: Universality or Prior Dependence?](http://arxiv.org/abs/1907.08095v1) (1907.08095v1)\n<i>Perseas Christodoulidis, Diederik Roest, Robert Rosati</b>\n\n<h10>2019-07-18</h10>\n> We investigate the observational signatures of many-field inflation and present analytic expressions for the spectral index as a function of the prior. For a given prior we employ the central limit theorem and the horizon crossing approximation to derive universal predictions, as found previously. However, we also find a specific dependence on the prior choice for initial conditions that has not been seen in previous studies. Our main focus is on quadratic inflation, for which the initial conditions statistics decouple from those of the mass distribution, while other monomials are also briefly discussed. We verify the validity of our calculations by comparing to full numerical simulations with ![](http://latex2png.com/output//latex_7e24dea1023c6600ef254be2b9cb6565.png) fields using the transport method.\n\n### [The galaxy bias at second order in general relativity with Non-Gaussian  initial conditions](http://arxiv.org/abs/1907.08094v1) (1907.08094v1)\n<i>Obinna Umeh, Kazuya Koyama</b>\n\n<h10>2019-07-18</h10>\n> We present a systematic study of galaxy bias in the presence of primordial non-Gaussianity in General Relativity (GR) at second order in perturbation theory. The non-linearity of the Poisson equation in GR and primordial non-Gaussianity are consistently included. We show that the inclusion of non-local primordial non-Gaussianity in addition to local non-Gaussianity is important to show the absence of the modulation of small scale clustering by the long-wavelength mode in the single field slow-roll inflation. We study the bispectrum of the relativistic galaxy density in several gauges and identify the effect of primordial non-Gaussianity and GR corrections.\n\n# <center>High Energy Astrophysical Phenomena</center> \n <hr> \n\n### [Inverse Compton emission from millisecond pulsars in the Galactic bulge](http://arxiv.org/abs/1901.07025v2) (1901.07025v2)\n<i>Deheng Song, Oscar Macias, Shunsaku Horiuchi</b>\n\n<h10>2019-01-21</h10>\n> Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly ![](http://latex2png.com/output//latex_174ac781ee40ce7c1db4f55851bbbc24.png)20 degrees in latitude. The leading theory postulates that this GeV excess is the aggregate emission from a large number of faint millisecond pulsars (MSPs). The electrons and positrons (![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png)) injected by this population could produce detectable inverse-Compton (IC) emissions by up-scattering ambient photons to gamma-ray energies. In this work, we calculate such IC emissions using GALPROP. A triaxial three-dimensional model of the bulge stars obtained from a fit to infrared data is used as a tracer of the putative MSP population. This model is compared against one in which the MSPs are spatially distributed as a Navarro-Frenk-White squared profile. We show that the resulting spectra for both models are indistinguishable, but that their spatial morphologies have salient recognizable features. The IC component above ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)TeV energies carries information on the spatial morphology of the injected ![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png). Such differences could potentially be used by future high-energy gamma-ray detectors such as the Cherenkov Telescope Array to provide a viable multiwavelength handle for the MSP origin of the GeV excess.\n\n### [Testing cosmology and fundamental physics with the Cherenkov Telescope  Array](http://arxiv.org/abs/1907.08141v1) (1907.08141v1)\n<i>H. Martínez-Huerta, J. Biteau, J. Lefaucheur, M. Meyer, S. Pita, I. Vovk</b>\n\n<h10>2019-07-18</h10>\n> The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray astronomy at energies above 30 GeV. Thanks to its unique capabilities, CTA observations will address a plethora of open questions in astrophysics ranging from the origin of cosmic messengers to the exploration of the frontiers of physics. In this note, we present a comprehensive sensitivity study to assess the potential of CTA to measure the ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray absorption on the extragalactic background light (EBL), to constrain or detect intergalactic magnetic fields (IGMFs), and probe physics beyond the Standard Model such as axion-like particles (ALPs) and Lorentz invariance violation (LIV), which could modify the ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray spectra features expected from EBL absorption. Our results suggest that CTA will have unprecedented sensitivity to detect IGMF signatures and will probe so-far unexplored regions of the LIV and ALP parameter space. Furthermore, an indirect measurement of the EBL and of its evolution will be performed with unrivaled precision.\n\n### [Segregation of Stellar-Mass Black Holes at the Galactic Center](http://arxiv.org/abs/1903.02578v3) (1903.02578v3)\n<i>Razieh Emami, Abraham Loeb</b>\n\n<h10>2019-03-06</h10>\n> We simulate the star cluster near the center of the Milky Way galaxy. Using the Fokker Planck approach we consider the time evolution of the density profile of stars and stellar mass black holes (BHs) for various initial profiles. BHs sink toward the center of the galaxy where they are swallowed by SgrA*. We show that the mass loss increases the mass of SgrA* by up to 20\\% for shallow initial radial profile with a power-law slope ![](http://latex2png.com/output//latex_764f39554b8e1a76b3e33973b7724bfc.png), and BH mass of ![](http://latex2png.com/output//latex_502b3c5b8372d6cb98bc1c5b907a8ca9.png). We model the consumption rate analytically and compare it with the results from simulation. Stars make the main contribution in increasing the mass of SgrA*. We show the growth of Bahcall-Wolf cusp in the density profile of BHs in agreement with direct N-body simulations.\n\n### [EmCa -- Electromagnetic-Cascades Simulation Package](http://arxiv.org/abs/1907.06924v2) (1907.06924v2)\n<i>Stephan Meighen-Berger, Anatoli Fedynitch, Matthias Huber</b>\n\n<h10>2019-07-16</h10>\n> Electromagnetic-Cascades (EmCa) is a Python package for the simulation of electromagnetic cascades in various materials. The showers are modeled using cascade equations and the relevant interactions, specifically pair production, Bremsstrahlung, Compton scattering and ionization. This methodology has the advantage of being computationally inexpensive and fast, unlike Monte Carlo methods. The code includes low and high energy material effects, allowing for a high range of validity of the simulation results. EmCa is easily extendable and offers a framework for testing different electromagnetic interaction models. In combination with MCEq, a Python package for hadronic particle showers using cascade equations, full simulations of atmospheric fluxes can be done.\n\n### [On the role of a cavity in the hypernova ejecta of GRB 190114C](http://arxiv.org/abs/1904.03163v4) (1904.03163v4)\n<i>R. Ruffini, J. D. Melon Fuksman, G. V. Vereshchagin</b>\n\n<h10>2019-04-05</h10>\n> Within the binary-driven hypernova I (BdHN I) scenario, the gamma-ray burst GRB190114C originates in a binary system composed of a massive carbon-oxygen core (CO![](http://latex2png.com/output//latex_6388b98e96a6dfb3adefe93eda59d45b.png)), and a binary neutron star (NS) companion. As the CO![](http://latex2png.com/output//latex_6388b98e96a6dfb3adefe93eda59d45b.png) undergoes a supernova explosion with the creation of a new neutron star (![](http://latex2png.com/output//latex_9572b94ee9291e7516491a08be107c07.png)NS), hypercritical accretion occurs onto the companion binary neutron star until it exceeds the critical mass for gravitational collapse. The formation of a black hole (BH) captures ![](http://latex2png.com/output//latex_44ed32f3bcc25c4ff8fc4e6346d446f3.png) baryons by enclosing them within its horizon, and thus a cavity of approximately ![](http://latex2png.com/output//latex_009105d3d731bc5075d6e324e6038219.png) cm is formed around it with initial density ![](http://latex2png.com/output//latex_f73fc73ec416f3faa0db4eb4472146df.png) g/cm![](http://latex2png.com/output//latex_3ab3261c243a6faefe22e74991dd6a96.png). A further depletion of baryons in the cavity originates from the expansion of the electron-positron-photon (![](http://latex2png.com/output//latex_9db91924f36f28e53a35fa1861cd46fb.png)) plasma formed at the collapse, reaching a density of ![](http://latex2png.com/output//latex_aac545525cd9c01cc76ed6bdd18c3c17.png) g/cm![](http://latex2png.com/output//latex_3ab3261c243a6faefe22e74991dd6a96.png) by the end of the interaction. It is demonstrated here using an analytical model complemented by a hydrodynamical numerical simulation that part of the ![](http://latex2png.com/output//latex_9db91924f36f28e53a35fa1861cd46fb.png) plasma is reflected off the walls of the cavity. The consequent outflow and its observed properties are shown to coincide with the featureless emission occurring in a time interval of duration ![](http://latex2png.com/output//latex_ee4a90454f1c12aa24fc95cca7d04488.png), measured in the rest frame of the source, between ![](http://latex2png.com/output//latex_57d2108e8bf558e5f85fd008628366f0.png) and ![](http://latex2png.com/output//latex_d820690da3b699516cff01eec847a032.png) s of the GBM observation. Moreover, similar features of the GRB light curve were previously observed in GRB 090926A and GRB 130427A, all belonging to the BdHN I class. This interpretation supports the general conceptual framework presented in Ruffini et al. (2019) and guarantees that a low baryon density is reached in the cavity, a necessary condition for the operation of the \"inner engine\" of the GRB presented in an accompanying article (Ruffini & Moradi 2019).\n\n# <center>Instrumentation And Methods In Astrophysics</center> \n <hr> \n\n### [Comparing Multi-class, Binary and Hierarchical Machine Learning  Classification schemes for variable stars](http://arxiv.org/abs/1907.08189v1) (1907.08189v1)\n<i>Zafiirah Hosenie, Robert Lyon, Benjamin Stappers, Arrykrishna Mootoovaloo</b>\n\n<h10>2019-07-18</h10>\n> Upcoming synoptic surveys are set to generate an unprecedented amount of data. This requires an automatic framework that can quickly and efficiently provide classification labels for several new object classification challenges. Using data describing 11 types of variable stars from the Catalina Real-Time Transient Surveys (CRTS), we illustrate how to capture the most important information from computed features and describe detailed methods of how to robustly use Information Theory for feature selection and evaluation. We apply three Machine Learning (ML) algorithms and demonstrate how to optimize these classifiers via cross-validation techniques. For the CRTS dataset, we find that the Random Forest (RF) classifier performs best in terms of balanced-accuracy and geometric means. We demonstrate substantially improved classification results by converting the multi-class problem into a binary classification task, achieving a balanced-accuracy rate of ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)99 per cent for the classification of ![](http://latex2png.com/output//latex_9b6f06e27b3c0947f4156ccd5ed540d0.png)-Scuti and Anomalous Cepheids (ACEP). Additionally, we describe how classification performance can be improved via converting a 'flat-multi-class' problem into a hierarchical taxonomy. We develop a new hierarchical structure and propose a new set of classification features, enabling the accurate identification of subtypes of cepheids, RR Lyrae and eclipsing binary stars in CRTS data.\n\n### [Entering into the Wide Field Adaptive Optics Era in the Northern  Hemisphere](http://arxiv.org/abs/1907.08169v1) (1907.08169v1)\n<i>Gaetano Sivo, John Blakeslee, Jennifer Lotz, Henry Roe, Morten Andersen, Julia Scharwachter, David Palmer, Scot Kleinman, Andy Adamson, Paul Hirst, Eduardo Marin, Laure Catala, Marcos van Dam, Stephen Goodsell, Natalie Provost, Ruben Diaz, Inger Jorgensen, Hwihyun Kim, Marie Lemoine-Busserole, Celia Blain, Mark Chun, Mark Ammons, Julian Christou, Charlotte Bond, Suresh Sivanandam, Paolo Turri, Peter Wizinowich, Carlos Correia, Benoit Neichel, Jean-Pierre Veran, Simone Esposito, Masen Lamb, Thierry Fusco, Francois Rigaut, Eric Steinbring</b>\n\n<h10>2019-07-18</h10>\n> As part of the National Science Foundation funded \"Gemini in the Era of MultiMessenger Astronomy\" (GEMMA) program, Gemini Observatory is developing GNAO, a widefield adaptive optics (AO) facility for Gemini-North on Maunakea, the only 8m-class open-access telescope available to the US astronomers in the northern hemisphere. GNAO will provide the user community with a queue-operated Multi-Conjugate AO (MCAO) system, enabling a wide range of innovative solar system, Galactic, and extragalactic science with a particular focus on synergies with JWST in the area of time-domain astronomy. The GNAO effort builds on institutional investment and experience with the more limited block-scheduled Gemini Multi-Conjugate System (GeMS), commissioned at Gemini South in 2013. The project involves close partnerships with the community through the recently established Gemini AO Working Group and the GNAO Science Team, as well as external instrument teams. The modular design of GNAO will enable a planned upgrade to a Ground Layer AO (GLAO) mode when combined with an Adaptive Secondary Mirror (ASM). By enhancing the natural seeing by an expected factor of two, GLAO will vastly improve Gemini North's observing efficiency for seeing-limited instruments and strengthen its survey capabilities for multi-messenger astronomy.\n\n### [Laboratory rotational spectroscopy of isotopic acetone,  CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png), and astronomical search in  Sagittarius B2(N2)](http://arxiv.org/abs/1907.08073v1) (1907.08073v1)\n<i>Matthias H. Ordu, Oliver Zingsheim, Arnaud Belloche, Frank Lewen, Robin T. Garrod, Karl M. Menten, Stephan Schlemmer, Holger S. P. Müller</b>\n\n<h10>2019-07-18</h10>\n> We want to study the rotational spectra of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and search for them in Sagittarius B2(N2). We investigated the laboratory rotational spectrum of isotopically enriched CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) between 40 GHz and 910 GHz and of acetone between 36 GHz and 910 GHz in order to study ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in natural isotopic composition. In addition, we searched for emission lines produced by these species in a molecular line survey of Sagittarius B2(N) carried out with ALMA. Discrepancies between predictions of the main isotopic species and the ALMA spectrum prompted us to revisit the rotational spectrum of this isotopolog. We assigned 9711 new transitions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and 63 new transitions of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in the laboratory spectra. More than 1000 additional lines were assigned for the main isotopic species. We modeled the ground state data of all three isotopologs satisfactorily with the ERHAM program. We find that models of the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) improve only marginally. No transition of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) is clearly detected toward the hot molecular core Sgr B2(N2). However, we report a tentative detection of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) with a ![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)C/![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)C isotopic ratio of 27 that is consistent with the ratio previously measured for alcohols in this source. Several dozens of transitions of both torsional states of the main isotopolog are detected as well. Our predictions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) are reliable into the terahertz region. The spectrum of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) should be revisited in the laboratory with an enriched sample. Transitions pertaining to the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) could be identified unambiguously in Sagittarius B2(N2).\n\n### [Monte Carlo study of a single SST-1M prototype for the Cherenkov  Telescope Array](http://arxiv.org/abs/1907.08061v1) (1907.08061v1)\n<i>Jakub Jurysek, Imen Al Samarai, Cyril Alispach, Matteo Balbo, Anastasia Maria Barbano, Vasyl Beshley, Adrian Biland, Jiri Blazek, Jacek Błocki, Jerzy Borkowski, Tomek Bulik, Frank Raphael Cadoux, Ladislav Chytka, Victor Coco, Nicolas De Angelis, Domenico Della Volpe, Yannick Favre, Tomasz Gieras, Mira Grudzińska, Petr Hamal, Mathieu Heller, Miroslav Hrabovsky, Jerzy Kasperek, Katarzyna Koncewicz, Andrzej Kotarba, Etienne Lyard, Emil Mach, Dusan Mandat, Stanislav Michal, Jerzy Michalowski, Rafal Moderski, Teresa Montaruli, Andrii Nagai, Dominik Neise, Jacek Niemiec, Theodore Rodrigue Njoh Ekoume, Michal Ostrowski, Miroslav Palatka, Pawel Pasko, Miroslav Pech, Bartłomiej Pilszyk, Henry Przybilski, Pawel Rajda, Yves Renier, Paweł Rozwadowski, Petr Schovanek, K. Seweryn, Vitalii Sliusar, Dorota Smakulska, Dorota Sobczyńska, Łukasz Stawarz, Jacek Świerblewski, Paweł Świerk, Petr Travnicek, Isaac Troyano Pujadas, Roland Walter, Marek Wiecek, Aleksander Zagdański, Krzystof Zietara</b>\n\n<h10>2019-07-18</h10>\n> The SST-1M telescope was developed as a prototype of a Small-Size-Telescope for the Cherenkov Telescope Array observatory and it has been extensively tested in Krakow since 2017. In this contribution we present validation of the Monte Carlo model of the prototype and expected performance in Krakow conditions. We focus on gamma/hadron separation and mono reconstruction of energy and gamma photon arrival direction using Machine learning methods.\n\n### [Embedding Climate Change Engagement in Astronomy Education and Research](http://arxiv.org/abs/1907.08043v1) (1907.08043v1)\n<i>Kathryn Williamson, Travis A. Rector, James Lowenthal</b>\n\n<h10>2019-07-18</h10>\n> This White Paper is a call to action for astronomers to respond to climate change with a large structural transition within our profession. Many astronomers are deeply concerned about climate change and act upon it in their personal and professional lives, and many organizations within astronomy have incorporated incremental changes. We need a collective impact model to better network and grow our efforts so that we can achieve results that are on the scale appropriate to address climate change at the necessary level indicated by scientific research; e.g., becoming carbon neutral by 2050. We need to implement strategies within two primary drivers of our field: (1) Education and Outreach, and (2) Research Practices and Infrastructure. (1) In the classroom and through public talks, astronomers reach a large audience. Astronomy is closely connected to the science of climate change, and it is arguably the most important topic we include in our curriculum. Due to misinformation and disinformation, climate change communication is different than for other areas of science. We therefore need to expand our communication and implement effective strategies, for which there is now a considerable body of research. (2) On a per-person basis astronomers have an outsized carbon impact. There are numerous ways we can reduce our footprint; e.g., in the design and operation of telescope facilities and in the optimization and reduction of travel. Fortunately, many of these solutions are win-win scenarios, e.g., increasing the online presence of conferences will reduce the carbon footprint while increasing participation, especially for astronomers working with fewer financial resources. Astronomers have an obligation to act on climate change in every way possible, and we need to do it now. In this White Paper, we outline a plan for collective impact using a Networked Improvement Community (NIC) approach.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics A |2019-07-20",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Astrophysics Of Galaxies</center> \n <hr> \n\n### [Inverse Compton emission from millisecond pulsars in the Galactic bulge](http://arxiv.org/abs/1901.07025v2) (1901.07025v2)\n<i>Deheng Song, Oscar Macias, Shunsaku Horiuchi</b>\n\n<h10>2019-01-21</h10>\n> Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly ![](http://latex2png.com/output//latex_174ac781ee40ce7c1db4f55851bbbc24.png)20 degrees in latitude. The leading theory postulates that this GeV excess is the aggregate emission from a large number of faint millisecond pulsars (MSPs). The electrons and positrons (![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png)) injected by this population could produce detectable inverse-Compton (IC) emissions by up-scattering ambient photons to gamma-ray energies. In this work, we calculate such IC emissions using GALPROP. A triaxial three-dimensional model of the bulge stars obtained from a fit to infrared data is used as a tracer of the putative MSP population. This model is compared against one in which the MSPs are spatially distributed as a Navarro-Frenk-White squared profile. We show that the resulting spectra for both models are indistinguishable, but that their spatial morphologies have salient recognizable features. The IC component above ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)TeV energies carries information on the spatial morphology of the injected ![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png). Such differences could potentially be used by future high-energy gamma-ray detectors such as the Cherenkov Telescope Array to provide a viable multiwavelength handle for the MSP origin of the GeV excess.\n\n### [Stellar and Dust Properties of a Complete Sample of Massive Dusty  Galaxies at ![](http://latex2png.com/output//latex_687d102cde5d9447a12d61c03b445e2a.png) from MAGPHYS Modeling of UltraVISTA DR3 and  Herschel Photometry](http://arxiv.org/abs/1907.08152v1) (1907.08152v1)\n<i>Nicholas S. Martis, Danilo M. Marchesini, Adam Muzzin, Mauro Stefanon, Gabriel Brammer, Elisabete da Cunha, Anna Sajina, Ivo Labbé</b>\n\n<h10>2019-07-18</h10>\n> We investigate the stellar and dust properties of massive (log![](http://latex2png.com/output//latex_36d6933ef3a1d279d7818f2897efbc64.png)) and dusty (![](http://latex2png.com/output//latex_a7602de34833e2deb98212db0e22a84a.png)) galaxies at ![](http://latex2png.com/output//latex_687d102cde5d9447a12d61c03b445e2a.png) by modeling their spectral energy distributions (SEDs) obtained from the combination of UltraVISTA DR3 photometry and \\textit{Herschel} PACS-SPIRE data using MAGPHYS. Although the rest-frame U-V vs V-J (UVJ) diagram traces well the star-formation rates (SFR) and dust obscuration (A![](http://latex2png.com/output//latex_48090e970ef5d526b553fe46671433d1.png)) out to ![](http://latex2png.com/output//latex_ce49f761a8620c968ffa75e0d2bfc096.png), ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)15-20\\% of the sample surprisingly resides in the quiescent region of the UVJ diagram, while ![](http://latex2png.com/output//latex_621ae1f65fc3f860567f1b758c86286b.png)\\% at ![](http://latex2png.com/output//latex_8fbbf165b26a10d18d10d079718d076d.png) fall in the unobscured star-forming region. The median SED of massive dusty galaxies exhibits weaker MIR and UV emission, and redder UV slopes with increasing cosmic time. The IR emission for our sample has a significant contribution (![](http://latex2png.com/output//latex_075568e24fa817c1e10dd3f585396878.png)) from dust heated by evolved stellar populations rather than star formation, demonstrating the need for panchromatic SED modeling. The local relation between dust mass and SFR is followed only by a sub-sample with cooler dust temperatures, while warmer objects have reduced dust masses at a given SFR. Most star-forming galaxies in our sample do not follow local IRX-![](http://latex2png.com/output//latex_a09ff5aa4faa8ac1a92a3e088b122835.png) relations, though IRX does strongly correlate with A![](http://latex2png.com/output//latex_48090e970ef5d526b553fe46671433d1.png). Our sample follows local relations, albeit with large scatter, between ISM diagnostics and sSFR. We show that FIR-detected sources represent the extreme of a continuous population of dusty galaxies rather than a fundamentally different population. Finally, using commonly adopted relations to derive SFRs from the combination of the rest-frame UV and the observed 24![](http://latex2png.com/output//latex_d6ab24fcd975e3392b48ba13cd4778fc.png)m is found to overestimate the SFR by a factor of 3-5 for the galaxies in our sample.\n\n### [Segregation of Stellar-Mass Black Holes at the Galactic Center](http://arxiv.org/abs/1903.02578v3) (1903.02578v3)\n<i>Razieh Emami, Abraham Loeb</b>\n\n<h10>2019-03-06</h10>\n> We simulate the star cluster near the center of the Milky Way galaxy. Using the Fokker Planck approach we consider the time evolution of the density profile of stars and stellar mass black holes (BHs) for various initial profiles. BHs sink toward the center of the galaxy where they are swallowed by SgrA*. We show that the mass loss increases the mass of SgrA* by up to 20\\% for shallow initial radial profile with a power-law slope ![](http://latex2png.com/output//latex_764f39554b8e1a76b3e33973b7724bfc.png), and BH mass of ![](http://latex2png.com/output//latex_502b3c5b8372d6cb98bc1c5b907a8ca9.png). We model the consumption rate analytically and compare it with the results from simulation. Stars make the main contribution in increasing the mass of SgrA*. We show the growth of Bahcall-Wolf cusp in the density profile of BHs in agreement with direct N-body simulations.\n\n### [Signatures of diffuse interstellar gas in the Galaxy Evolution Explorer  all sky survey](http://arxiv.org/abs/1907.08099v1) (1907.08099v1)\n<i>Marcelo Armengot, Ana I. Gomez de Castro</b>\n\n<h10>2019-07-18</h10>\n> The all sky survey run by the Galaxy Evolution Explorer (GALEX AIS) mapped about 85\\% of the Galaxy at ultraviolet (UV) wavelengths and detected the diffuse UV background produced by the scattering of the radiation from OBA stars by interstellar dust grains. Against this background, diffuse weak structures are detected as well as the UV counterparts to nebulae and molecular clouds. To make full profit of the survey, unsupervised and semi-supervised procedures need to be implemented. The main objective of this work is to implement and analyze the results of the method developed by us for the blind detection of ISM features in the GALEX AIS . Most ISM features are detected at very low signal levels (dark filaments, globules) against the already faint UV background. We have defined an index, the UV background fluctuations index (or UBF index), to identify areas of the sky where these fluctuations are detected. The algorithm is applied to the images obtained in the FUV 1344 -- 1786 Angstroms) band since this is less polluted by stellar sources, facilitating the automated detection. The UBF index is shown to be sensitive to the main star forming regions within the Gould's Belt, as well as to some prominent loops like Loop I or the Eridanus and Monogem areas. The catalogue with the UBF index values is made available on-line to the community.\n\n### [Laboratory rotational spectroscopy of isotopic acetone,  CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png), and astronomical search in  Sagittarius B2(N2)](http://arxiv.org/abs/1907.08073v1) (1907.08073v1)\n<i>Matthias H. Ordu, Oliver Zingsheim, Arnaud Belloche, Frank Lewen, Robin T. Garrod, Karl M. Menten, Stephan Schlemmer, Holger S. P. Müller</b>\n\n<h10>2019-07-18</h10>\n> We want to study the rotational spectra of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and search for them in Sagittarius B2(N2). We investigated the laboratory rotational spectrum of isotopically enriched CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) between 40 GHz and 910 GHz and of acetone between 36 GHz and 910 GHz in order to study ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in natural isotopic composition. In addition, we searched for emission lines produced by these species in a molecular line survey of Sagittarius B2(N) carried out with ALMA. Discrepancies between predictions of the main isotopic species and the ALMA spectrum prompted us to revisit the rotational spectrum of this isotopolog. We assigned 9711 new transitions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and 63 new transitions of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in the laboratory spectra. More than 1000 additional lines were assigned for the main isotopic species. We modeled the ground state data of all three isotopologs satisfactorily with the ERHAM program. We find that models of the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) improve only marginally. No transition of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) is clearly detected toward the hot molecular core Sgr B2(N2). However, we report a tentative detection of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) with a ![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)C/![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)C isotopic ratio of 27 that is consistent with the ratio previously measured for alcohols in this source. Several dozens of transitions of both torsional states of the main isotopolog are detected as well. Our predictions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) are reliable into the terahertz region. The spectrum of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) should be revisited in the laboratory with an enriched sample. Transitions pertaining to the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) could be identified unambiguously in Sagittarius B2(N2).\n\n# <center>Earth And Planetary Astrophysics</center> \n <hr> \n\n### [Martian Year 34 Column Dust Climatology from Mars Climate Sounder  Observations: Reconstructed Maps and Model Simulations](http://arxiv.org/abs/1907.08187v1) (1907.08187v1)\n<i>Luca Montabone, Aymeric Spiga, David M. Kass, Armin Kleinböhl, François Forget, Ehouarn Millour</b>\n\n<h10>2019-07-18</h10>\n> We have reconstructed longitude-latitude maps of column dust optical depth (CDOD) for Martian year (MY) 34 (May 5, 2017 --- March 23, 2019) using observations by the Mars Climate Sounder (MCS) aboard NASA's Mars Reconnaissance Orbiter spacecraft. Our methodology works by gridding standard and newly available estimates of CDOD from MCS limb observations, using the \"iterative weighted binning\" methodology. In this work, we reconstruct four gridded CDOD maps per sol, at different Mars Universal Times. Together with the seasonal and day-to-day variability, the use of several maps per sol allows to explore also the daily variability of CDOD in the MCS dataset, which is shown to be particularly strong during the MY 34 equinoctial Global Dust Event (GDE). Regular maps of CDOD are then produced by daily averaging and spatially interpolating the irregularly gridded maps using a standard \"kriging\" interpolator, and can be used as \"dust scenario\" for numerical model simulations. In order to understand whether the daily variability of CDOD has a physical explanation, we have carried out numerical simulations with the \"Laboratoire de M\\'et\\'eorologie Dynamique\" Mars Global Climate Model. Using a \"free dust\" run initiated at ![](http://latex2png.com/output//latex_cb747fcfb5a7c79cb2bce2a95fffbae0.png) with the corresponding kriged map, but subsequently free of further CDOD forcing, we show that the model is able to account for some of the observed daily variability in CDOD. The model serves also to confirm that the use of the MY 34 daily-averaged dust scenario in a GCM produces results consistent with those obtained for the MY 25 GDE.\n\n### [Parametric study of polar configurations around binaries](http://arxiv.org/abs/1907.08180v1) (1907.08180v1)\n<i>Cristian Giuppone, Nicolás Cuello</b>\n\n<h10>2019-07-18</h10>\n> Dynamical studies suggest that most of the circumbinary discs (CBDs) should be coplanar. However, under certain initial conditions, the CBD can evolve toward polar orientation. Here we extend the parametric study of polar configurations around detached close-in binaries through ![](http://latex2png.com/output//latex_b9e69f0f03051ff98f89be64ae45918f.png)-body simulations. For polar configurations around binaries with mass ratios ![](http://latex2png.com/output//latex_8252603f68bd2a6b7e714e5055bdac3d.png) below ![](http://latex2png.com/output//latex_c174e69b59fb25a86e3f276774fcfc6f.png), the nominal location of the mean motion resonance (MMR) ![](http://latex2png.com/output//latex_403228beb8df83fca1ede3b87e641313.png) predicts the limit of stability for ![](http://latex2png.com/output//latex_4b022dd92ae67442ac01e19b96a74083.png). Alternatively, for ![](http://latex2png.com/output//latex_3d2dd7ecb84849ef6cadcbcb4bc8ef76.png) or ![](http://latex2png.com/output//latex_45508835633b63f8e8a286d5d26dd555.png), the nominal location of the MMR ![](http://latex2png.com/output//latex_baceaca3abc651537dff6e5075f8a35c.png) is the closest stable region. The presence of a} giant planet increases the region of forbidden polar configurations around low mass ratio binaries with eccentricities ![](http://latex2png.com/output//latex_feb072c4f98da11bdc2850e676bd106d.png) with respect to rocky earth-like planets. For equal mass stars, the eccentricity excitation ![](http://latex2png.com/output//latex_6331d6100b52a4af90d24c003741a702.png) of polar orbits smoothly increases with decreasing distance to the binary. For ![](http://latex2png.com/output//latex_079d841a67b4e71c51e7b105df062512.png), ![](http://latex2png.com/output//latex_6331d6100b52a4af90d24c003741a702.png) can reach values as high as ![](http://latex2png.com/output//latex_ab7c1933e38fc63e865a89d38a75641e.png). Finally, we studied polar configurations around ![](http://latex2png.com/output//latex_a91a77936d0f58bf2860a8664c55f92a.png) and show that the region of stability is strongly affected by the relative positions of the nodes. The most stable configurations in the system correspond to polar particles, which are not expected to survive on longer time-scales due to the presence of the external perturber HD~![](http://latex2png.com/output//latex_5074a8fb06751561a86123638b647ec9.png).\n\n### [Geochemistry constrains global hydrology on Early Mars](http://arxiv.org/abs/1907.08166v1) (1907.08166v1)\n<i>Edwin S. Kite, Mohit Melwani Daswani</b>\n\n<h10>2019-07-18</h10>\n> Ancient hydrology is recorded by sedimentary rocks on Mars. The most voluminous sedimentary rocks that formed during Mars' Hesperian period are sulfate-rich rocks, explored by the ![](http://latex2png.com/output//latex_1a261583ce2a8cd37288ba32b4c2fc8d.png) rover from 2004-2012 and soon to be investigated by the ![](http://latex2png.com/output//latex_6d132474afc6a522c3ebe2fded21235e.png) rover at Gale crater. A leading hypothesis for the origin of these sulfates is that the cations were derived from evaporation of deep-sourced groundwater, as part of a global circulation of groundwater. Global groundwater circulation would imply sustained warm Earthlike conditions on Early Mars. Global circulation of groundwater including infiltration of water initially in equilibrium with Mars' CO![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) atmosphere implies subsurface formation of carbonate. We find that the CO![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) sequestration implied by the global groundwater hypothesis for the origin of sulfate-rich rocks on Mars is 30-5000 bars if the ![](http://latex2png.com/output//latex_1a261583ce2a8cd37288ba32b4c2fc8d.png) data are representative of Hesperian sulfate-rich rocks, which is so large that (even accounting for volcanic outgassing) it would bury the atmosphere. This disfavors the hypothesis that the cations for Mars' Hesperian sulfates were derived from upwelling of deep sourced groundwater. If, instead, Hesperian sulfate-rich rocks are approximated as pure Mg-sulfate (no Fe), then the CO![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) sequestration is 0.3-400 bars. The low end of this range is consistent with the hypothesis that the cations for Mars' Hesperian sulfates were derived from upwelling of deep sourced groundwater. In both cases, carbon sequestration by global groundwater circulation actively works to terminate surface habitability, rather than being a passive marker of warm Earthlike conditions. ![](http://latex2png.com/output//latex_6d132474afc6a522c3ebe2fded21235e.png) will soon be in a position to discriminate between these two hypotheses. Our work links Mars sulfate cation composition, carbon isotopes, and climate change.\n\n### [The multiplicity distribution of Kepler's exoplanets](http://arxiv.org/abs/1907.08148v1) (1907.08148v1)\n<i>Emily Sandford, David Kipping, Michael Collins</b>\n\n<h10>2019-07-18</h10>\n> The true multiplicity distribution of transiting planet systems is obscured by strong observational biases, leading low-multiplicity systems to be overrepresented in the observed sample. Using the Kepler FGK planet hosts, we employ approximate Bayesian computation to infer the multiplicity distribution by comparing simulated catalogs to the observed one. After comparing a total of ten different multiplicity distributions, half of which were two-population models, to the observed data, we find that a single-population model following a Zipfian distribution is able to explain the Kepler data as well as any of the dichotomous models we test. Our work provides another example of a way to explain the observed Kepler multiplicities without invoking a dichotomous planet population. Using our preferred Zipfian model, we estimate that an additional ![](http://latex2png.com/output//latex_ff9f96cee7fbd1b8518786e9ccba8529.png) planets likely reside in the 1537 FGK Kepler systems studied in this work, which would increase the planet count by a factor of ![](http://latex2png.com/output//latex_648663d43d776586082481e7de8bc851.png). Of these hidden worlds, ![](http://latex2png.com/output//latex_3d14ebbdb47afb29e0c0db4f8f057300.png) are expected to reside in ostensibly single-transiting-planet systems, meaning that an additional planet(s) is expected for approximately 1-in-2 such Kepler systems.\n\n### [Observational constraints on dust disk sizes in tidally truncated  protoplanetary disks in multiple systems in the Taurus region](http://arxiv.org/abs/1907.03846v3) (1907.03846v3)\n<i>C. F. Manara, M. Tazzari, F. Long, G. J. Herczeg, G. Lodato, A. A. Rota, P. Cazzoletti, G. van der Plas, P. Pinilla, G. Dipierro, S. Edwards, D. Harsono, D. Johnstone, Y. Liu, F. Menard, B. Nisini, E. Ragusa, Y. Boehler, S. Cabrit</b>\n\n<h10>2019-07-08</h10>\n> The impact of stellar multiplicity on the evolution of planet-forming disks is still the subject of debate. Here we present and analyze disk structures around ten multiple stellar systems that were included in an unbiased, high spatial resolution survey performed with ALMA of 32 protoplanetary disks in the Taurus star-forming region. At the unprecedented spatial resolution of ~0.12\" we detect and spatially resolve the disks around all primary stars, and those around eight secondary and one tertiary star. The dust radii of disks around multiple stellar systems are smaller than those around single stars in the same stellar mass range and in the same region. The disks in multiple stellar systems also show a steeper decay of the millimeter continuum emission at the outer radius than disks around single stars, suggestive of the impact of tidal truncation on the shape of the disks in multiple systems. However, the observed ratio between the dust disk radii and the observed separation of the stars in the multiple systems is consistent with analytic predictions of the effect of tidal truncation only if the eccentricities of the binaries are rather high (typically >0.5), or if the observed dust radii are a factor of two smaller than the gas radii, as is typical for isolated systems. Similar high-resolution studies targeting the gaseous emission from disks in multiple stellar systems are required to resolve this question.\n\n# <center>Solar And Stellar Astrophysics</center> \n <hr> \n\n### [Formation of quasi-periodic slow magnetoacoustic wave trains by the  heating/cooling misbalance](http://arxiv.org/abs/1907.08168v1) (1907.08168v1)\n<i>D. I. Zavershinskii, D. Y. Kolotkov, V. M. Nakariakov, N. E. Molevich, D. S. Ryashchikov</b>\n\n<h10>2019-07-18</h10>\n> Slow magnetoacoustic waves are omnipresent in both natural and laboratory plasma systems. The wave-induced misbalance between plasma cooling and heating processes causes the amplification or attenuation, and also dispersion, of slow magnetoacoustic waves. The wave dispersion could be attributed to the presence of characteristic time scales in the system, connected with the plasma heating or cooling due to the competition of the heating and cooling processes in the vicinity of the thermal equilibrium. We analysed linear slow magnetoacoustic waves in a plasma in a thermal equilibrium formed by a balance of optically thin radiative losses, field-align thermal conduction, and an unspecified heating. The dispersion is manifested by the dependence of the effective adiabatic index of the wave on the wave frequency, making the phase and group speeds frequency-dependent. The mutual effect of the wave amplification and dispersion is shown to result into the occurrence of an oscillatory pattern in an initially broadband slow wave, with the characteristic period determined by the thermal misbalance time scales, i.e. by the derivatives of the combined radiation loss and heating function with respect to the density and temperature, evaluated at the equilibrium. This effect is illustrated by estimating the characteristic period of the oscillatory pattern, appearing because of thermal misbalance in the plasma of the solar corona. It is found that by an order of magnitude the period is about the typical periods of slow magnetoacoustic oscillations detected in the corona.\n\n### [Rigidly rotating, incompressible spheroid-ring systems: new  bifurcations, critical rotations and degenerate states](http://arxiv.org/abs/1907.08151v1) (1907.08151v1)\n<i>B. Basillais, J. -M. Huré</b>\n\n<h10>2019-07-18</h10>\n> The equilibrium of incompressible spheroid-ring systems in rigid rotation is investigated by numerical means for a unity density contrast. A great diversity of binary configurations is obtained, with no limit neither in the mass ratio, nor in the orbital separation. We found only detached binaries, meaning that the end-point of the ![](http://latex2png.com/output//latex_4383d7038c11cbc2515d0d3c1a530eb6.png)-sequence is the single binary state in strict contact, easily prone to mass-exchange. The solutions show a remarkable confinement in the rotation frequency-angular momentum diagram, with a total absence of equilibrium for ![](http://latex2png.com/output//latex_eac07c47f35f11702e14d9dd84258461.png). A short band of degeneracy is present next to the one-ring sequence. We unveil a continuum of bifurcations all along the ascending side of the Maclaurin sequence for eccentricities of the ellipsoid less than ![](http://latex2png.com/output//latex_3b05b022917e94bb7a101c56caf09ad1.png) and which involves a gradually expanding, initially massless loop.\n\n### [Observational constraints on dust disk sizes in tidally truncated  protoplanetary disks in multiple systems in the Taurus region](http://arxiv.org/abs/1907.03846v3) (1907.03846v3)\n<i>C. F. Manara, M. Tazzari, F. Long, G. J. Herczeg, G. Lodato, A. A. Rota, P. Cazzoletti, G. van der Plas, P. Pinilla, G. Dipierro, S. Edwards, D. Harsono, D. Johnstone, Y. Liu, F. Menard, B. Nisini, E. Ragusa, Y. Boehler, S. Cabrit</b>\n\n<h10>2019-07-08</h10>\n> The impact of stellar multiplicity on the evolution of planet-forming disks is still the subject of debate. Here we present and analyze disk structures around ten multiple stellar systems that were included in an unbiased, high spatial resolution survey performed with ALMA of 32 protoplanetary disks in the Taurus star-forming region. At the unprecedented spatial resolution of ~0.12\" we detect and spatially resolve the disks around all primary stars, and those around eight secondary and one tertiary star. The dust radii of disks around multiple stellar systems are smaller than those around single stars in the same stellar mass range and in the same region. The disks in multiple stellar systems also show a steeper decay of the millimeter continuum emission at the outer radius than disks around single stars, suggestive of the impact of tidal truncation on the shape of the disks in multiple systems. However, the observed ratio between the dust disk radii and the observed separation of the stars in the multiple systems is consistent with analytic predictions of the effect of tidal truncation only if the eccentricities of the binaries are rather high (typically >0.5), or if the observed dust radii are a factor of two smaller than the gas radii, as is typical for isolated systems. Similar high-resolution studies targeting the gaseous emission from disks in multiple stellar systems are required to resolve this question.\n\n### [First detections of H13CO+ and HC15N in the disk around HD 97048:  Evidence for a cold gas reservoir in the outer disk](http://arxiv.org/abs/1907.08060v1) (1907.08060v1)\n<i>Alice S. Booth, Catherine Walsh, John D. Ilee</b>\n\n<h10>2019-07-18</h10>\n> Observations of different molecular lines in protoplanetary disks provide valuable information on the gas kinematics, as well as constraints on the radial density and temperature structure of the gas. With ALMA we have detected H13CO+ (J=4-3) and HC15N (J=4-3) in the HD97048 protoplanetary disk for the first time. We compare these new detections to the ringed continuum mm-dust emission and the spatially resolved CO (J=3-2) and HCO+ (J=4-3) emission. The radial distributions of the H13CO+ and HC15N emission show hints of ringed sub-structure whereas, the optically thick tracers, CO and HCO+, do not. We calculate the HCO+/H13CO+ intensity ratio across the disk and find that it is radially constant (within our uncertainties). We use a physio-chemical parametric disk structure of the HD97048 disk with an analytical prescription for the HCO+ abundance distribution to generate synthetic observations of the HCO+ and H13CO+ disk emission assuming LTE. The best by-eye fit models require radial variations in the HCO+/H13CO+ abundance ratio and an overall enhancement in H13CO+ relative to HCO+. This highlights the need to consider isotope selective chemistry and in particular low temperature carbon isotope exchange reactions. This also points to the presence of a reservoir of cold molecular gas in the outer disk (T < 10K, R > 200au). Chemical models are required to confirm that isotope-selective chemistry alone can explain the observations presented here. With these data, we cannot rule out that the known dust substructure in the HD97048 disk is responsible for the observed trends in molecular line emission, and higher spatial resolution observations are required to fully explore the potential of optically thin tracers to probe planet-carved dust gaps. We also report non-detections of H13CO+ and HC15N in the HD100546 protoplanetary disk.\n\n### [The Tayler Instability in the Anelastic Approximation](http://arxiv.org/abs/1808.08958v2) (1808.08958v2)\n<i>J. Goldstein, R. H. D. Townsend, E. G. Zweibel</b>\n\n<h10>2018-08-27</h10>\n> The Tayler instability (TI) is a non-axisymmetric linear instability of an axisymmetric toroidal magnetic field in magneto-hydrostatic equilibrium (MHSE). Spruit (1999, 2002) has proposed that in a differentially rotating radiative region of a star, the TI drives a dynamo which generates magnetic fields that can efficiently transport angular momentum; a parameterized version of this dynamo has been implemented in stellar structure and evolution codes and shown to be important for determining interior spin. Numerical simulations, however, have yet to definitively demonstrate the operation of the dynamo. A criterion for the MHSE to develop the TI was derived using fully-compressible magneto-hydrodynamics, while numerical simulations of dynamical processes in stars frequently use an anelastic approximation. This motivates us to derive a new anelastic Tayler instability (anTI) criterion. We find that some MHSE configurations unstable in the fully-compressible case, become stable in the anelastic case. We find and characterize the unstable modes of a simple family of cylindrical MHSE configurations using numerical calculations, and discuss the implications for fully non-linear anelastic simulations.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "permlink": "latest-arxiv-papers-in-astrophysics-b-2019-07-19",
      "title": "Latest Arxiv Papers In Astrophysics B |2019-07-19",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Cosmology And Nongalactic Astrophysics</center> \n <hr> \n\n### [Death by Dark Matter](http://arxiv.org/abs/1907.06674v2) (1907.06674v2)\n<i>Jagjit Singh Sidhu, Robert J Scherrer, Glenn Starkman</b>\n\n<h10>2019-07-15</h10>\n> Macroscopic dark matter refers to a variety of dark matter candidates that would be expected to (elastically) scatter off of ordinary matter with a large geometric cross-section. A wide range of macro masses ![](http://latex2png.com/output//latex_68ced1eb95810d385dabc9cddd66e64f.png) and cross-sections ![](http://latex2png.com/output//latex_0901868ab589a1b9a3787cca4a3037a2.png) remain unprobed. We show that over a wide region within the unexplored parameter space, collisions of a macro with a human body would result in serious injury or death. We use the absence of such unexplained impacts with a well-monitored subset of the human population to exclude a region bounded by ![](http://latex2png.com/output//latex_732773455ebc7b557b6e43220584822e.png) cm![](http://latex2png.com/output//latex_c325d54e893a48d5fd764007d924c553.png) and ![](http://latex2png.com/output//latex_09bf0583ab443f87be42bda3077e03fb.png) kg. Our results open a new window on dark matter: the human body as a dark matter detector.\n\n### [Early Structure Formation in ![](http://latex2png.com/output//latex_57ab36b2298729499dff5ca89c1efe4e.png)PBH Cosmologies](http://arxiv.org/abs/1907.08129v1) (1907.08129v1)\n<i>Derek Inman, Yacine Ali-Haïmoud</b>\n\n<h10>2019-07-18</h10>\n> Cold dark matter (CDM) could be composed of primordial black holes (PBH) in addition to or instead of more orthodox weakly interacting massive particle dark matter (PDM). We study the formation of the first structures in such ![](http://latex2png.com/output//latex_2c5a069424a79c8fac46c445901441e6.png)PBH cosmologies using ![](http://latex2png.com/output//latex_b9e69f0f03051ff98f89be64ae45918f.png)-body simulations evolved from deep in the radiation era to redshift 99. When PBH are only a small component of the CDM, they are clothed by PDM to form isolated halos. On the other hand, when PBH make most of the CDM, halos can also grow via clustering of many PBH. We find that the halo mass function is well modelled via Poisson statistics assuming random initial conditions. We quantify the nonlinear velocities induced by structure formation and find that they are too small to significantly impact CMB constraints. A chief challenge is how best to extrapolate our results to lower redshifts relevant for some observational constraints.\n\n### [Estimates of Fast Radio Burst Dispersion Measures from Cosmological  Simulations](http://arxiv.org/abs/1903.07630v2) (1903.07630v2)\n<i>N. Pol, M. T. Lam, M. A. McLaughlin, T. J. W. Lazio, J. M. Cordes</b>\n\n<h10>2019-03-18</h10>\n> We calculate the dispersion measure (DM) contributed by the intergalactic medium (IGM) to the total measured DM for fast radio bursts (FRBs). We use the MareNostrum Instituto de Ciencias del Espacio (MICE) Onion Universe simulation (Fosalba et al. 2008) to track the evolution of the dark matter particle density over a large range of redshifts. We convert this dark matter particle number density to the corresponding free electron density and then integrate it to find the DM as a function of redshift. This approach yields an intergalactic DM of ![](http://latex2png.com/output//latex_e73f3093ae5a2ff9c166e258e3bc7e76.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png), with the large errors representative of the structure in the IGM. We place limits on the redshifts of the current population of observed FRBs. We also use our results to estimate the host galaxy contribution to the DM for the first repeater, FRB 121102, and show that the most probable host galaxy DM contribution, ![](http://latex2png.com/output//latex_742de1d03fb5145d3fa6f2011bb1a463.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png), is consistent with the estimate made using the Balmer emission lines in the spectrum of the host galaxy, ![](http://latex2png.com/output//latex_77fdfb1b5106b7ba25a5e971283eb17e.png) pc cm![](http://latex2png.com/output//latex_43050100a4c9ae1f88f6237456bb2702.png) (Tendulkar et al. 2017). We also compare our predictions for the host galaxy contribution to the DM for the observations of FRB 180924 (Bannister et al. 2019) and FRB 190523 (Ravi et al. 2019), both of which have been localized to a host galaxy.\n\n### [Many-field Inflation: Universality or Prior Dependence?](http://arxiv.org/abs/1907.08095v1) (1907.08095v1)\n<i>Perseas Christodoulidis, Diederik Roest, Robert Rosati</b>\n\n<h10>2019-07-18</h10>\n> We investigate the observational signatures of many-field inflation and present analytic expressions for the spectral index as a function of the prior. For a given prior we employ the central limit theorem and the horizon crossing approximation to derive universal predictions, as found previously. However, we also find a specific dependence on the prior choice for initial conditions that has not been seen in previous studies. Our main focus is on quadratic inflation, for which the initial conditions statistics decouple from those of the mass distribution, while other monomials are also briefly discussed. We verify the validity of our calculations by comparing to full numerical simulations with ![](http://latex2png.com/output//latex_7e24dea1023c6600ef254be2b9cb6565.png) fields using the transport method.\n\n### [The galaxy bias at second order in general relativity with Non-Gaussian  initial conditions](http://arxiv.org/abs/1907.08094v1) (1907.08094v1)\n<i>Obinna Umeh, Kazuya Koyama</b>\n\n<h10>2019-07-18</h10>\n> We present a systematic study of galaxy bias in the presence of primordial non-Gaussianity in General Relativity (GR) at second order in perturbation theory. The non-linearity of the Poisson equation in GR and primordial non-Gaussianity are consistently included. We show that the inclusion of non-local primordial non-Gaussianity in addition to local non-Gaussianity is important to show the absence of the modulation of small scale clustering by the long-wavelength mode in the single field slow-roll inflation. We study the bispectrum of the relativistic galaxy density in several gauges and identify the effect of primordial non-Gaussianity and GR corrections.\n\n# <center>High Energy Astrophysical Phenomena</center> \n <hr> \n\n### [Inverse Compton emission from millisecond pulsars in the Galactic bulge](http://arxiv.org/abs/1901.07025v2) (1901.07025v2)\n<i>Deheng Song, Oscar Macias, Shunsaku Horiuchi</b>\n\n<h10>2019-01-21</h10>\n> Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly ![](http://latex2png.com/output//latex_174ac781ee40ce7c1db4f55851bbbc24.png)20 degrees in latitude. The leading theory postulates that this GeV excess is the aggregate emission from a large number of faint millisecond pulsars (MSPs). The electrons and positrons (![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png)) injected by this population could produce detectable inverse-Compton (IC) emissions by up-scattering ambient photons to gamma-ray energies. In this work, we calculate such IC emissions using GALPROP. A triaxial three-dimensional model of the bulge stars obtained from a fit to infrared data is used as a tracer of the putative MSP population. This model is compared against one in which the MSPs are spatially distributed as a Navarro-Frenk-White squared profile. We show that the resulting spectra for both models are indistinguishable, but that their spatial morphologies have salient recognizable features. The IC component above ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)TeV energies carries information on the spatial morphology of the injected ![](http://latex2png.com/output//latex_d64bdf7192386be9f6d68b888d4c8dd3.png). Such differences could potentially be used by future high-energy gamma-ray detectors such as the Cherenkov Telescope Array to provide a viable multiwavelength handle for the MSP origin of the GeV excess.\n\n### [Testing cosmology and fundamental physics with the Cherenkov Telescope  Array](http://arxiv.org/abs/1907.08141v1) (1907.08141v1)\n<i>H. Martínez-Huerta, J. Biteau, J. Lefaucheur, M. Meyer, S. Pita, I. Vovk</b>\n\n<h10>2019-07-18</h10>\n> The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray astronomy at energies above 30 GeV. Thanks to its unique capabilities, CTA observations will address a plethora of open questions in astrophysics ranging from the origin of cosmic messengers to the exploration of the frontiers of physics. In this note, we present a comprehensive sensitivity study to assess the potential of CTA to measure the ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray absorption on the extragalactic background light (EBL), to constrain or detect intergalactic magnetic fields (IGMFs), and probe physics beyond the Standard Model such as axion-like particles (ALPs) and Lorentz invariance violation (LIV), which could modify the ![](http://latex2png.com/output//latex_03b3d3c34db979f91f61324978833de2.png)-ray spectra features expected from EBL absorption. Our results suggest that CTA will have unprecedented sensitivity to detect IGMF signatures and will probe so-far unexplored regions of the LIV and ALP parameter space. Furthermore, an indirect measurement of the EBL and of its evolution will be performed with unrivaled precision.\n\n### [Segregation of Stellar-Mass Black Holes at the Galactic Center](http://arxiv.org/abs/1903.02578v3) (1903.02578v3)\n<i>Razieh Emami, Abraham Loeb</b>\n\n<h10>2019-03-06</h10>\n> We simulate the star cluster near the center of the Milky Way galaxy. Using the Fokker Planck approach we consider the time evolution of the density profile of stars and stellar mass black holes (BHs) for various initial profiles. BHs sink toward the center of the galaxy where they are swallowed by SgrA*. We show that the mass loss increases the mass of SgrA* by up to 20\\% for shallow initial radial profile with a power-law slope ![](http://latex2png.com/output//latex_764f39554b8e1a76b3e33973b7724bfc.png), and BH mass of ![](http://latex2png.com/output//latex_502b3c5b8372d6cb98bc1c5b907a8ca9.png). We model the consumption rate analytically and compare it with the results from simulation. Stars make the main contribution in increasing the mass of SgrA*. We show the growth of Bahcall-Wolf cusp in the density profile of BHs in agreement with direct N-body simulations.\n\n### [EmCa -- Electromagnetic-Cascades Simulation Package](http://arxiv.org/abs/1907.06924v2) (1907.06924v2)\n<i>Stephan Meighen-Berger, Anatoli Fedynitch, Matthias Huber</b>\n\n<h10>2019-07-16</h10>\n> Electromagnetic-Cascades (EmCa) is a Python package for the simulation of electromagnetic cascades in various materials. The showers are modeled using cascade equations and the relevant interactions, specifically pair production, Bremsstrahlung, Compton scattering and ionization. This methodology has the advantage of being computationally inexpensive and fast, unlike Monte Carlo methods. The code includes low and high energy material effects, allowing for a high range of validity of the simulation results. EmCa is easily extendable and offers a framework for testing different electromagnetic interaction models. In combination with MCEq, a Python package for hadronic particle showers using cascade equations, full simulations of atmospheric fluxes can be done.\n\n### [On the role of a cavity in the hypernova ejecta of GRB 190114C](http://arxiv.org/abs/1904.03163v4) (1904.03163v4)\n<i>R. Ruffini, J. D. Melon Fuksman, G. V. Vereshchagin</b>\n\n<h10>2019-04-05</h10>\n> Within the binary-driven hypernova I (BdHN I) scenario, the gamma-ray burst GRB190114C originates in a binary system composed of a massive carbon-oxygen core (CO![](http://latex2png.com/output//latex_6388b98e96a6dfb3adefe93eda59d45b.png)), and a binary neutron star (NS) companion. As the CO![](http://latex2png.com/output//latex_6388b98e96a6dfb3adefe93eda59d45b.png) undergoes a supernova explosion with the creation of a new neutron star (![](http://latex2png.com/output//latex_9572b94ee9291e7516491a08be107c07.png)NS), hypercritical accretion occurs onto the companion binary neutron star until it exceeds the critical mass for gravitational collapse. The formation of a black hole (BH) captures ![](http://latex2png.com/output//latex_44ed32f3bcc25c4ff8fc4e6346d446f3.png) baryons by enclosing them within its horizon, and thus a cavity of approximately ![](http://latex2png.com/output//latex_009105d3d731bc5075d6e324e6038219.png) cm is formed around it with initial density ![](http://latex2png.com/output//latex_f73fc73ec416f3faa0db4eb4472146df.png) g/cm![](http://latex2png.com/output//latex_3ab3261c243a6faefe22e74991dd6a96.png). A further depletion of baryons in the cavity originates from the expansion of the electron-positron-photon (![](http://latex2png.com/output//latex_9db91924f36f28e53a35fa1861cd46fb.png)) plasma formed at the collapse, reaching a density of ![](http://latex2png.com/output//latex_aac545525cd9c01cc76ed6bdd18c3c17.png) g/cm![](http://latex2png.com/output//latex_3ab3261c243a6faefe22e74991dd6a96.png) by the end of the interaction. It is demonstrated here using an analytical model complemented by a hydrodynamical numerical simulation that part of the ![](http://latex2png.com/output//latex_9db91924f36f28e53a35fa1861cd46fb.png) plasma is reflected off the walls of the cavity. The consequent outflow and its observed properties are shown to coincide with the featureless emission occurring in a time interval of duration ![](http://latex2png.com/output//latex_ee4a90454f1c12aa24fc95cca7d04488.png), measured in the rest frame of the source, between ![](http://latex2png.com/output//latex_57d2108e8bf558e5f85fd008628366f0.png) and ![](http://latex2png.com/output//latex_d820690da3b699516cff01eec847a032.png) s of the GBM observation. Moreover, similar features of the GRB light curve were previously observed in GRB 090926A and GRB 130427A, all belonging to the BdHN I class. This interpretation supports the general conceptual framework presented in Ruffini et al. (2019) and guarantees that a low baryon density is reached in the cavity, a necessary condition for the operation of the \"inner engine\" of the GRB presented in an accompanying article (Ruffini & Moradi 2019).\n\n# <center>Instrumentation And Methods In Astrophysics</center> \n <hr> \n\n### [Comparing Multi-class, Binary and Hierarchical Machine Learning  Classification schemes for variable stars](http://arxiv.org/abs/1907.08189v1) (1907.08189v1)\n<i>Zafiirah Hosenie, Robert Lyon, Benjamin Stappers, Arrykrishna Mootoovaloo</b>\n\n<h10>2019-07-18</h10>\n> Upcoming synoptic surveys are set to generate an unprecedented amount of data. This requires an automatic framework that can quickly and efficiently provide classification labels for several new object classification challenges. Using data describing 11 types of variable stars from the Catalina Real-Time Transient Surveys (CRTS), we illustrate how to capture the most important information from computed features and describe detailed methods of how to robustly use Information Theory for feature selection and evaluation. We apply three Machine Learning (ML) algorithms and demonstrate how to optimize these classifiers via cross-validation techniques. For the CRTS dataset, we find that the Random Forest (RF) classifier performs best in terms of balanced-accuracy and geometric means. We demonstrate substantially improved classification results by converting the multi-class problem into a binary classification task, achieving a balanced-accuracy rate of ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)99 per cent for the classification of ![](http://latex2png.com/output//latex_9b6f06e27b3c0947f4156ccd5ed540d0.png)-Scuti and Anomalous Cepheids (ACEP). Additionally, we describe how classification performance can be improved via converting a 'flat-multi-class' problem into a hierarchical taxonomy. We develop a new hierarchical structure and propose a new set of classification features, enabling the accurate identification of subtypes of cepheids, RR Lyrae and eclipsing binary stars in CRTS data.\n\n### [Entering into the Wide Field Adaptive Optics Era in the Northern  Hemisphere](http://arxiv.org/abs/1907.08169v1) (1907.08169v1)\n<i>Gaetano Sivo, John Blakeslee, Jennifer Lotz, Henry Roe, Morten Andersen, Julia Scharwachter, David Palmer, Scot Kleinman, Andy Adamson, Paul Hirst, Eduardo Marin, Laure Catala, Marcos van Dam, Stephen Goodsell, Natalie Provost, Ruben Diaz, Inger Jorgensen, Hwihyun Kim, Marie Lemoine-Busserole, Celia Blain, Mark Chun, Mark Ammons, Julian Christou, Charlotte Bond, Suresh Sivanandam, Paolo Turri, Peter Wizinowich, Carlos Correia, Benoit Neichel, Jean-Pierre Veran, Simone Esposito, Masen Lamb, Thierry Fusco, Francois Rigaut, Eric Steinbring</b>\n\n<h10>2019-07-18</h10>\n> As part of the National Science Foundation funded \"Gemini in the Era of MultiMessenger Astronomy\" (GEMMA) program, Gemini Observatory is developing GNAO, a widefield adaptive optics (AO) facility for Gemini-North on Maunakea, the only 8m-class open-access telescope available to the US astronomers in the northern hemisphere. GNAO will provide the user community with a queue-operated Multi-Conjugate AO (MCAO) system, enabling a wide range of innovative solar system, Galactic, and extragalactic science with a particular focus on synergies with JWST in the area of time-domain astronomy. The GNAO effort builds on institutional investment and experience with the more limited block-scheduled Gemini Multi-Conjugate System (GeMS), commissioned at Gemini South in 2013. The project involves close partnerships with the community through the recently established Gemini AO Working Group and the GNAO Science Team, as well as external instrument teams. The modular design of GNAO will enable a planned upgrade to a Ground Layer AO (GLAO) mode when combined with an Adaptive Secondary Mirror (ASM). By enhancing the natural seeing by an expected factor of two, GLAO will vastly improve Gemini North's observing efficiency for seeing-limited instruments and strengthen its survey capabilities for multi-messenger astronomy.\n\n### [Laboratory rotational spectroscopy of isotopic acetone,  CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png), and astronomical search in  Sagittarius B2(N2)](http://arxiv.org/abs/1907.08073v1) (1907.08073v1)\n<i>Matthias H. Ordu, Oliver Zingsheim, Arnaud Belloche, Frank Lewen, Robin T. Garrod, Karl M. Menten, Stephan Schlemmer, Holger S. P. Müller</b>\n\n<h10>2019-07-18</h10>\n> We want to study the rotational spectra of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and search for them in Sagittarius B2(N2). We investigated the laboratory rotational spectrum of isotopically enriched CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) between 40 GHz and 910 GHz and of acetone between 36 GHz and 910 GHz in order to study ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in natural isotopic composition. In addition, we searched for emission lines produced by these species in a molecular line survey of Sagittarius B2(N) carried out with ALMA. Discrepancies between predictions of the main isotopic species and the ALMA spectrum prompted us to revisit the rotational spectrum of this isotopolog. We assigned 9711 new transitions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and 63 new transitions of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) in the laboratory spectra. More than 1000 additional lines were assigned for the main isotopic species. We modeled the ground state data of all three isotopologs satisfactorily with the ERHAM program. We find that models of the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) improve only marginally. No transition of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) is clearly detected toward the hot molecular core Sgr B2(N2). However, we report a tentative detection of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) with a ![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)C/![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)C isotopic ratio of 27 that is consistent with the ratio previously measured for alcohols in this source. Several dozens of transitions of both torsional states of the main isotopolog are detected as well. Our predictions of CH![](http://latex2png.com/output//latex_8b68a38f5bfe79cbbf802c01f4297708.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) and CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) are reliable into the terahertz region. The spectrum of ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) should be revisited in the laboratory with an enriched sample. Transitions pertaining to the torsionally excited states ![](http://latex2png.com/output//latex_a6508c849d8195b8fc6a487e6b809133.png) and ![](http://latex2png.com/output//latex_e73dc0ee51afbea4a704ca111d83f423.png) of CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)C(O)CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png) could be identified unambiguously in Sagittarius B2(N2).\n\n### [Monte Carlo study of a single SST-1M prototype for the Cherenkov  Telescope Array](http://arxiv.org/abs/1907.08061v1) (1907.08061v1)\n<i>Jakub Jurysek, Imen Al Samarai, Cyril Alispach, Matteo Balbo, Anastasia Maria Barbano, Vasyl Beshley, Adrian Biland, Jiri Blazek, Jacek Błocki, Jerzy Borkowski, Tomek Bulik, Frank Raphael Cadoux, Ladislav Chytka, Victor Coco, Nicolas De Angelis, Domenico Della Volpe, Yannick Favre, Tomasz Gieras, Mira Grudzińska, Petr Hamal, Mathieu Heller, Miroslav Hrabovsky, Jerzy Kasperek, Katarzyna Koncewicz, Andrzej Kotarba, Etienne Lyard, Emil Mach, Dusan Mandat, Stanislav Michal, Jerzy Michalowski, Rafal Moderski, Teresa Montaruli, Andrii Nagai, Dominik Neise, Jacek Niemiec, Theodore Rodrigue Njoh Ekoume, Michal Ostrowski, Miroslav Palatka, Pawel Pasko, Miroslav Pech, Bartłomiej Pilszyk, Henry Przybilski, Pawel Rajda, Yves Renier, Paweł Rozwadowski, Petr Schovanek, K. Seweryn, Vitalii Sliusar, Dorota Smakulska, Dorota Sobczyńska, Łukasz Stawarz, Jacek Świerblewski, Paweł Świerk, Petr Travnicek, Isaac Troyano Pujadas, Roland Walter, Marek Wiecek, Aleksander Zagdański, Krzystof Zietara</b>\n\n<h10>2019-07-18</h10>\n> The SST-1M telescope was developed as a prototype of a Small-Size-Telescope for the Cherenkov Telescope Array observatory and it has been extensively tested in Krakow since 2017. In this contribution we present validation of the Monte Carlo model of the prototype and expected performance in Krakow conditions. We focus on gamma/hadron separation and mono reconstruction of energy and gamma photon arrival direction using Machine learning methods.\n\n### [Embedding Climate Change Engagement in Astronomy Education and Research](http://arxiv.org/abs/1907.08043v1) (1907.08043v1)\n<i>Kathryn Williamson, Travis A. Rector, James Lowenthal</b>\n\n<h10>2019-07-18</h10>\n> This White Paper is a call to action for astronomers to respond to climate change with a large structural transition within our profession. Many astronomers are deeply concerned about climate change and act upon it in their personal and professional lives, and many organizations within astronomy have incorporated incremental changes. We need a collective impact model to better network and grow our efforts so that we can achieve results that are on the scale appropriate to address climate change at the necessary level indicated by scientific research; e.g., becoming carbon neutral by 2050. We need to implement strategies within two primary drivers of our field: (1) Education and Outreach, and (2) Research Practices and Infrastructure. (1) In the classroom and through public talks, astronomers reach a large audience. Astronomy is closely connected to the science of climate change, and it is arguably the most important topic we include in our curriculum. Due to misinformation and disinformation, climate change communication is different than for other areas of science. We therefore need to expand our communication and implement effective strategies, for which there is now a considerable body of research. (2) On a per-person basis astronomers have an outsized carbon impact. There are numerous ways we can reduce our footprint; e.g., in the design and operation of telescope facilities and in the optimization and reduction of travel. Fortunately, many of these solutions are win-win scenarios, e.g., increasing the online presence of conferences will reduce the carbon footprint while increasing participation, especially for astronomers working with fewer financial resources. Astronomers have an obligation to act on climate change in every way possible, and we need to do it now. In this White Paper, we outline a plan for collective impact using a Networked Improvement Community (NIC) approach.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics A |2019-07-19",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Astrophysics Of Galaxies</center> \n <hr> \n\n### [Helium and Nitrogen Enrichment in Massive Main Sequence Stars:  Mechanisms and Implications for the Origin of WNL Stars](http://arxiv.org/abs/1907.07666v1) (1907.07666v1)\n<i>Arpita Roy, Ralph S Sutherland, Mark R Krumholz, Alexander Heger, Michael A Dopita</b>\n\n<h10>2019-07-17</h10>\n> The evolutionary paths taken by very massive stars, ![](http://latex2png.com/output//latex_9e346e9ef2bf755556c2ebb670dd3d1b.png), remain substantially uncertain: they begin their lives as main sequence O stars, but, depending on their masses, rotation rates, and metallicities, can then pass through a wide range of evolutionary states, yielding an equally broad set of possible surface compositions and spectral classifications. Here we present a new grid of calculations for the evolution of such stars, covering a broad range in mass (M/M![](http://latex2png.com/output//latex_d1f5e04a4901783f79f328235e893cac.png)), rotation rate (v/v![](http://latex2png.com/output//latex_c05ef9512fe4f64ca6c0833f06a48c44.png)), metallicity (![](http://latex2png.com/output//latex_c4ff391d63a3eaea5ccb192a4048deb5.png)), and ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png)-element enhancement (![](http://latex2png.com/output//latex_bd8fe0d89ea430cc8c7c032c2a12e7fd.png)). We show that rotating stars undergo rotationally-induced dredge-up of nucleosynthetic products, mostly He and N, to their surfaces while still on the main sequence. Non-rotating metal-rich stars also reveal the products of nucleosynthesis on their surfaces because even modest amounts of mass loss expose their \"fossil\" convective cores: regions that are no longer convective, but which were part of the convective core at an early stage in the star's evolution. Thus surface enhancement of He and N is expected for rotating stars at all metallicities, and for non-rotating stars if they are relatively metal-rich. We calculate a stellar atmosphere for a representative model from our grid, properly accounting for He- and N-enhancement, and show that the resulting spectrum provides a good match to observed WNL stars, strongly suggesting that the physical mechanisms we have identified are the ultimate cause of the WNL phase of massive stellar evolution. We conclude that this phase has important implications for the ionizing spectra of early galaxies.\n\n### [Rest-frame UV and optical emission line diagnostics of ionised gas  properties: a test case in a star-forming knot of a lensed galaxy at z~1.7](http://arxiv.org/abs/1907.07665v1) (1907.07665v1)\n<i>Ayan Acharyya, Lisa J. Kewley, Jane R. Rigby, Matthew Bayliss, Fuyan Bian, David Nicholls, Christoph Federrath, Melanie Kaasinen, Michael Florian, Guillermo A. Blanc</b>\n\n<h10>2019-07-17</h10>\n> We examine the diagnostic power of rest-frame ultraviolet (UV) nebular emission lines, and compare them to more commonly used rest-frame optical emission lines, using the test case of a single star-forming knot of the bright lensed galaxy RCSGA 032727-132609 at redshift z~1.7. This galaxy has complete coverage of all the major rest-frame UV and optical emission lines from Magellan/MagE and Keck/NIRSPEC. Using the full suite of diagnostic lines, we infer the physical properties: nebular electron temperature (T_e), electron density (n_e), oxygen abundance (log(O/H)), ionisation parameter (log(q)) and interstellar medium (ISM) pressure (log(P/k)). We examine the effectiveness of the different UV, optical and joint UV-optical spectra in constraining the physical conditions. Using UV lines alone we can reliably estimate log(q), but the same is difficult for log(O/H). UV lines yield a higher (~1.5 dex) log(P/k) than the optical lines, as the former probes a further inner nebular region than the latter. For this comparison, we extend the existing Bayesian inference code IZI, adding to it the capability to infer ISM pressure simultaneously with metallicity and ionisation parameter. This work anticipates future rest-frame UV spectral datasets from the James Webb Space Telescope (JWST) at high redshift and from the Extremely Large Telescope (ELT) at moderate redshift.\n\n### [Dense cores and star formation in the giant molecular cloud Vela~C](http://arxiv.org/abs/1907.07609v1) (1907.07609v1)\n<i>F. Massi, A. Weiss, D. Elia, T. Csengeri, E. Schisano, T. Giannini, T. Hill, D. Lorenzetti, K. Menten, L. Olmi, F. Schuller, F. Strafella, M. De Luca, F. Motte, F. Wyrowski</b>\n\n<h10>2019-07-17</h10>\n> Context The Vela Molecular Ridge is one of the nearest (700 pc) giant molecular cloud (GMC) complexes hosting intermediate-mass (up to early B, late O stars) star formation, and is located in the outer Galaxy, inside the Galactic plane. Vela C is one of the GMCs making up the Vela Molecular Ridge, and exhibits both sub-regions of robust and sub-regions of more quiescent star formation activity, with both low- and intermediate(high)-mass star formation in progress. Aims We aim to study the individual and global properties of dense dust cores in Vela C, and aim to search for spatial variations in these properties which could be related to different environmental properties and/or evolutionary stages in the various sub-regions of Vela C. Methods We mapped the submillimetre (345 GHz) emission from vela C with LABOCA (beam size 19.2\", spatial resolution ~0.07 pc at 700 pc) at the APEX telescope. We used the clump-finding algorithm CuTEx to identify the compact submillimetre sources. We also used SIMBA (250 GHz) observations, and Herschel and WISE ancillary data. The association with WISE red sources allowed the protostellar and starless cores to be separated, whereas the Herschel dataset allowed the dust temperature to be derived for a fraction of cores. The protostellar and starless core mass functions (CMFs) were constructed following two different approaches, achieving a mass completeness limit of 3.7 Msun. Results We retrieved 549 submillimetre cores, 316 of which are starless and mostly gravitationally bound (therefore prestellar in nature). Both the protostellar and the starless CMFs are consistent with the shape of a Salpeter initial mass function in the high-mass part of the distribution. Clustering of cores at scales of 1--6 pc is also found, hinting at fractionation of magnetised, turbulent gas.\n\n### [Widespread QSO-driven outflows in the early Universe](http://arxiv.org/abs/1806.00786v4) (1806.00786v4)\n<i>M. Bischetti, R. Maiolino, S. Carniani. F. Fiore, E. Piconcelli, A. Fluetsch</b>\n\n<h10>2018-06-03</h10>\n> We present the stacking analysis of a sample of 48 QSOs at 4.5<z<7.1 detected by ALMA in the [CII] 158 micron line to investigate the presence and the properties of massive, cold outflows traced by broad [CII] wings. We reveal very broad [CII] wings tracing the presence of outflows with velocities in excess of 1000 km/s. We find that the luminosity of the broad [CII] emission increases with LAGN, while it does not significantly depend on the SFR of the host galaxy, indicating that the central AGN is the main driving mechanism of the [CII] outflows in these powerful, distant QSOs. From the stack of the ALMA cubes, we derive an average outflow spatial extent of ~3.5 kpc. The average mass outflow rate inferred from the whole sample stack is ~ 100 Msun/yr, while for the most luminous systems it increases to ~200 Msun/yr. The associated outflow kinetic power is about 0.1% of LAGN, while the outflow momentum rate is about LAGN/c or lower, suggesting that these outflows are either driven by radiation pressure onto dusty clouds or, alternatively, are driven by the nuclear wind and energy conserving but with low coupling with the ISM. We discuss the implications of the resulting feedback effect on galaxy evolution in the early Universe.\n\n### [Charting nearby dust clouds using Gaia data only](http://arxiv.org/abs/1901.05971v3) (1901.05971v3)\n<i>R. H. Leike, T. A. Enßlin</b>\n\n<h10>2019-01-17</h10>\n> Aims: Highly resolved maps of the local Galactic dust are an important ingredient for sky emission models. In nearly the whole electromagnetic spectrum one can see imprints of dust, many of which originate from dust clouds within 300pc. Having a detailed 3D reconstruction of these local dust clouds enables detailed studies, helps to quantify the impact on other observables and is a milestone necessary to enable larger reconstructions, as every sightline for more distant objects will pass through the local dust.   Methods: To infer the dust density we use parallax and absorption estimates published by the Gaia collaboration in their second data release. We model the dust as a log-normal process using a hierarchical Bayesian model. We also infer non-parametrically the kernel of the log-normal process, which corresponds to the physical spatial correlation power spectrum of the log-density.   Results: Using only Gaia data of the second Gaia data release, we reconstruct the 3D dust density and its spatial correlation spectrum in a 600pc cube centered on the Sun. We report a spectral index of the logarithmic dust density of ![](http://latex2png.com/output//latex_c3f4fe2553f80c1435c04df7a85c283b.png) on Fourier scales with wavelengths between 2pc and 125pc. The resulting 3D dust map as well as the power spectrum and posterior samples are publicly available for download.\n\n# <center>Earth And Planetary Astrophysics</center> \n <hr> \n\n### [Constraining the initial planetary population in the gravitational  instability model](http://arxiv.org/abs/1907.07584v1) (1907.07584v1)\n<i>Jaxk Humphries, Allona Vazan, Mariangela Bonavita, Ravit Helled, Sergei Nayakshin</b>\n\n<h10>2019-07-17</h10>\n> Direct imaging (DI) surveys suggest that gas giants beyond 20 AU are rare around FGK stars. However, it is not clear what this means for the formation frequency of Gravitational Instability (GI) protoplanets due to uncertainties in gap opening and migration efficiency. Here we combine state-of-the-art calculations of homogeneous planet contraction with a population synthesis code. We find DI constraints to be satisfied if protoplanet formation by GI occurs in tens of percent of systems if protoplanets `super migrate' to small separations. In contrast, GI may occur in only a few percent of systems if protoplanets remain stranded at wide orbits because their migration is `quenched' by efficient gap opening. We then use the frequency of massive giants in radial velocity surveys inside 5 AU to break this degeneracy - observations recently showed that this population does not correlate with the host star metallicity and is therefore suspected to have formed via GI followed by inward migration. We find that only the super-migration scenario can sufficiently explain this population whilst simultaneously satisfying the DI constraints and producing the right mass spectrum of planets inside 5 AU. If massive gas-giants inside 5 AU formed via GI, then our models imply that migration must be efficient and that the formation of GI protoplanets occurs in at least a tens of percent of systems.\n\n### [Assessment of the probability of microbial contamination for sample  return from Martian moons II: The fate of microbes on Martian moons](http://arxiv.org/abs/1907.07576v1) (1907.07576v1)\n<i>Kosuke Kurosawa, Hidenori Genda, Ryuki Hyodo, Akihiko Yamagishi, Takashi Mikouchi, Takafumi Niihara, Shingo Matsuyama, Kazuhisa Fujita</b>\n\n<h10>2019-07-17</h10>\n> This paper presents a case study of microbe transportation in the Mars-satellites system. We examined the spatial distribution of potential impact-transported microbes on the Martian moons using impact physics by following a companion study (Fujita et al.). We used sterilization data from the precede studies. We considered that the microbes came mainly from the Zunil crater on Mars. We found that 70-80% of the microbes are likely to be dispersed all over the moon surface and are rapidly sterilized due to radiation except for those microbes within a thick ejecta deposit produced by meteoroids. The other 20-30% might be shielded from radiation by thick regolith layers that formed at collapsed layers in craters produced by Mars rock impacts. The total number of potentially surviving microbes at the thick ejecta deposits is estimated to be 3-4 orders of magnitude lower than at the Mars rock craters. The microbe concentration is irregular in the horizontal direction and is largely depth-dependent due to the radiation sterilization. The surviving fraction of transported microbes would be only 1 ppm on Phobos and 100 ppm on Deimos, suggesting that the transport processes and radiation severely affect microbe survival. The microbe sampling probability from the Martian moons was also investigated. We suggest that sample return missions from the Martian moons are classified into Unrestricted Earth-Return missions for 30 g samples and 10 cm depth sampling, even in our conservative scenario. We also conducted a full statistical analysis for sampling the regolith of Phobos to include the effects of uncertainties in input parameters on the sampling probability. The most likely probability of microbial contamination for return samples is estimated to be two orders of magnitude lower than the criterion defined by the planetary protection policy of the Committee on Space Research (COSPAR).\n\n### [Assessment of the probability of microbial contamination for sample  return from Martian moons I: Departure of microbes from Martian surface](http://arxiv.org/abs/1907.07575v1) (1907.07575v1)\n<i>Kazuhisa Fujita, Kosuke Kurosawa, Hidenori Genda, Ryuki Hyodo, Shingo Matsuyama, Akihiko Yamagishi, Takashi Mikouchi, Takafumi Niihara</b>\n\n<h10>2019-07-17</h10>\n> Potential microbial contamination of Martian moons, Phobos and Deimos, which can be brought about by transportation of Mars ejecta produced by meteoroid impacts on the Martian surface, has been comprehensively assessed in a statistical approach, based on the most probable history of recent major gigantic meteoroid collisions on the Martian surface. This article is the first part of our study to assess potential microbial density in Mars ejecta departing from the Martian atmosphere, as a source of the second part where statistical analysis of microbial contamination probability is conducted. Potential microbial density on the Martian surface as the source of microorganisms was estimated by analogy to the terrestrial areas having the similar arid and cold environments, from which a probabilistic function was deduced as the asymptotic limit. Microbial survival rate during hypervelocity meteoroid collisions was estimated by numerical analysis of impact phenomena with and without taking internal friction and plastic deformation of the colliding meteoroid and the target ground into consideration. Trajectory calculations of departing ejecta through the Martian atmosphere were conducted with taking account of aerodynamic deceleration and heating by the aid of computational fluid dynamic analysis. It is found that Mars ejecta smaller than 0.03 m in diameter hardly reach the Phobos orbit due to aerodynamic deceleration, or mostly sterilized due to significant aerodynamic heating even though they can reach the Phobos orbit and beyond. Finally, the baseline dataset of microbial density in Mars ejecta departing for Martian moons has been presented for the second part of our study.\n\n### [Observational constraints on dust disk sizes in tidally truncated  protoplanetary disks in multiple systems in the Taurus region](http://arxiv.org/abs/1907.03846v2) (1907.03846v2)\n<i>C. F. Manara, M. Tazzari, F. Long, G. J. Herczeg, G. Lodato, A. A. Rota, P. Cazzoletti, G. van der Plas, P. Pinilla, G. Dipierro, S. Edwards, D. Harsono, D. Johnstone, Y. Liu, F. Menard, B. Nisini, E. Ragusa, Y. Boehler, S. Cabrit</b>\n\n<h10>2019-07-08</h10>\n> The impact of stellar multiplicity on the evolution of planet-forming disks is still the subject of debate. Here we present and analyze disk structures around ten multiple stellar systems that were included in an unbiased, high spatial resolution survey performed with ALMA of 32 protoplanetary disks in the Taurus star-forming region. At the unprecedented spatial resolution of ~0.12\" we detect and spatially resolve the disks around all primary stars, and those around eight secondary and one tertiary star. The dust radii of disks around multiple stellar systems are smaller than those around single stars in the same stellar mass range and in the same region. The disks in multiple stellar systems also show a steeper decay of the millimeter continuum emission at the outer radius than disks around single stars, suggestive of the impact of tidal truncation on the shape of the disks in multiple systems. However, the observed ratio between the dust disk radii and the observed separation of the stars in the multiple systems is consistent with analytic predictions of the effect of tidal truncation only if the eccentricities of the binaries are rather high (typically >0.5), or if the observed dust radii are a factor of two smaller than the gas radii, as is typical for isolated systems. Similar high-resolution studies targeting the gaseous emission from disks in multiple stellar systems are required to resolve this question.\n\n### [Role of planetary obliquity in regulating atmospheric escape: G-dwarf  vs. M-dwarf Earth-like exoplanets](http://arxiv.org/abs/1907.07459v1) (1907.07459v1)\n<i>Chuanfei Dong, Zhenguang Huang, Manasvi Lingam</b>\n\n<h10>2019-07-17</h10>\n> We present a three-species multi-fluid MHD model (H![](http://latex2png.com/output//latex_c129308d9ed369e2c743821a83dc927d.png), O![](http://latex2png.com/output//latex_c129308d9ed369e2c743821a83dc927d.png) and e![](http://latex2png.com/output//latex_3db7472b2dff59a7a3b040ffb618bf6b.png)), endowed with the requisite upper atmospheric chemistry, that is capable of accurately quantifying the magnitude of oxygen ion losses from \"Earth-like\" exoplanets in habitable zones, whose magnetic and rotational axes are roughly coincidental with one another. We apply this model to investigate the role of planetary obliquity in regulating atmospheric losses from a magnetic perspective. For Earth-like exoplanets orbiting solar-type stars, we demonstrate that the dependence of the total atmospheric ion loss rate on the planetary (magnetic) obliquity is relatively weak; the escape rates are found to vary between ![](http://latex2png.com/output//latex_494d62f80335ea38964632e85c318feb.png) s![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png) to ![](http://latex2png.com/output//latex_6e1612f0c6d510b73df3fa8a6ab9ca9f.png) s![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png). In contrast, the obliquity can influence the atmospheric escape rate (![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png) ![](http://latex2png.com/output//latex_d88de845c280371e7ab0dcf8a2af035a.png) s![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png)) by more than a factor of ![](http://latex2png.com/output//latex_26daae761df47424c2024c19ed468273.png) (or ![](http://latex2png.com/output//latex_b9f2abaae7418af35788dc408f5370fb.png)) in the case of Earth-like exoplanets orbiting late-type M-dwarfs. Thus, our simulations indicate that planetary obliquity may play a weak-to-moderate role insofar as the retention of an atmosphere (necessary for surface habitability) is concerned.\n\n# <center>Solar And Stellar Astrophysics</center> \n <hr> \n\n### [Helium and Nitrogen Enrichment in Massive Main Sequence Stars:  Mechanisms and Implications for the Origin of WNL Stars](http://arxiv.org/abs/1907.07666v1) (1907.07666v1)\n<i>Arpita Roy, Ralph S Sutherland, Mark R Krumholz, Alexander Heger, Michael A Dopita</b>\n\n<h10>2019-07-17</h10>\n> The evolutionary paths taken by very massive stars, ![](http://latex2png.com/output//latex_9e346e9ef2bf755556c2ebb670dd3d1b.png), remain substantially uncertain: they begin their lives as main sequence O stars, but, depending on their masses, rotation rates, and metallicities, can then pass through a wide range of evolutionary states, yielding an equally broad set of possible surface compositions and spectral classifications. Here we present a new grid of calculations for the evolution of such stars, covering a broad range in mass (M/M![](http://latex2png.com/output//latex_d1f5e04a4901783f79f328235e893cac.png)), rotation rate (v/v![](http://latex2png.com/output//latex_c05ef9512fe4f64ca6c0833f06a48c44.png)), metallicity (![](http://latex2png.com/output//latex_c4ff391d63a3eaea5ccb192a4048deb5.png)), and ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png)-element enhancement (![](http://latex2png.com/output//latex_bd8fe0d89ea430cc8c7c032c2a12e7fd.png)). We show that rotating stars undergo rotationally-induced dredge-up of nucleosynthetic products, mostly He and N, to their surfaces while still on the main sequence. Non-rotating metal-rich stars also reveal the products of nucleosynthesis on their surfaces because even modest amounts of mass loss expose their \"fossil\" convective cores: regions that are no longer convective, but which were part of the convective core at an early stage in the star's evolution. Thus surface enhancement of He and N is expected for rotating stars at all metallicities, and for non-rotating stars if they are relatively metal-rich. We calculate a stellar atmosphere for a representative model from our grid, properly accounting for He- and N-enhancement, and show that the resulting spectrum provides a good match to observed WNL stars, strongly suggesting that the physical mechanisms we have identified are the ultimate cause of the WNL phase of massive stellar evolution. We conclude that this phase has important implications for the ionizing spectra of early galaxies.\n\n### [Stellar cooling anomalies and variant axion models](http://arxiv.org/abs/1907.07662v1) (1907.07662v1)\n<i>Ken'ichi Saikawa, Tsutomu T. Yanagida</b>\n\n<h10>2019-07-17</h10>\n> A number of observations of stellar systems show a mild preference for anomalously fast cooling compared with what predicted in the standard theory, which leads to a speculation that there exists an additional energy loss mechanism originated from the emission of axions in stars. We explore the possibility that such excessive energy losses are interpreted in the framework of variant axion models, which require two Higgs doublets and flavor-dependent Peccei-Quinn charge assignments. These models resolve two fundamental issues faced in the traditional KSVZ/DFSZ models by predicting a sizable axion coupling to electrons required to explain the cooling anomalies and at the same time providing a solution to the cosmological domain wall problem. We also find that a specific structure of the axion couplings to electrons and nucleons slightly relaxes the constraint from supernova 1987A and enlarges viable parameter regions compared with the DFSZ models. It is shown that good global fits to the observational data are obtained for axion mass ranges of ![](http://latex2png.com/output//latex_f021ef1d14b6324d6a50e685c1f3d287.png), and that the predicted parameter regions can be probed in the forthcoming helioscope searches.\n\n### [Signatures for quark matter from multi-messenger observations](http://arxiv.org/abs/1904.05471v3) (1904.05471v3)\n<i>Mark G. Alford, Sophia Han, Kai Schwenzer</b>\n\n<h10>2019-04-10</h10>\n> We review the prospects for detecting quark matter in neutron star cores. We survey the proposed signatures and emphasize the importance of data from neutron star mergers, which provide access to dynamical properties that operate on short timescales that are not probed by other neutron star observables.\n\n### [Self-lensing Discovery of a ![](http://latex2png.com/output//latex_31dadbd65f88158e66872e1329746585.png) White Dwarf in an Unusually  Wide Orbit Around a Sun-like Star](http://arxiv.org/abs/1907.07656v1) (1907.07656v1)\n<i>Kento Masuda, Hajime Kawahara, David W. Latham, Allyson Bieryla, Masanobu Kunitomo, Morgan MacLeod, Wako Aoki</b>\n\n<h10>2019-07-17</h10>\n> We report the discovery of the fifth self-lensing binary in which a low-mass white dwarf (WD) gravitationally magnifies its 15th magnitude G-star companion, KIC 8145411, during eclipses. The system was identified from a pair of such self-lensing events in the Kepler photometry, and was followed up with the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5m telescope at the Fred Lawrence Whipple Observatory and the High-Dispersion Spectrograph (HDS) on the Subaru 8.2m telescope. A joint analysis of the TRES radial velocities, the HDS spectrum, and the Kepler photometry of the primary star determines the WD mass ![](http://latex2png.com/output//latex_14259d9a92d8ec38385e236e0ef821d5.png), orbital semi-major axis ![](http://latex2png.com/output//latex_e0a09a0e6d2f2e1fe07d7fe8ee157257.png), and orbital eccentricity ![](http://latex2png.com/output//latex_c741034d48b88bea879f7e72c0d2c602.png). Because such extremely low-mass WDs cannot be formed in isolation within the age of the Galaxy, their formation is believed to involve binary interactions that truncated evolution of the WD progenitor. However, the observed orbit of the KIC 8145411 system is at least ten times wider than required for this scenario to work. The presence of this system in the Kepler sample, along with its similarities to field blue straggler binaries presumably containing WDs, may suggest that some 10% of post-AGB binaries with Sun-like primaries contain such anomalous WDs.\n\n### [Dense cores and star formation in the giant molecular cloud Vela~C](http://arxiv.org/abs/1907.07609v1) (1907.07609v1)\n<i>F. Massi, A. Weiss, D. Elia, T. Csengeri, E. Schisano, T. Giannini, T. Hill, D. Lorenzetti, K. Menten, L. Olmi, F. Schuller, F. Strafella, M. De Luca, F. Motte, F. Wyrowski</b>\n\n<h10>2019-07-17</h10>\n> Context The Vela Molecular Ridge is one of the nearest (700 pc) giant molecular cloud (GMC) complexes hosting intermediate-mass (up to early B, late O stars) star formation, and is located in the outer Galaxy, inside the Galactic plane. Vela C is one of the GMCs making up the Vela Molecular Ridge, and exhibits both sub-regions of robust and sub-regions of more quiescent star formation activity, with both low- and intermediate(high)-mass star formation in progress. Aims We aim to study the individual and global properties of dense dust cores in Vela C, and aim to search for spatial variations in these properties which could be related to different environmental properties and/or evolutionary stages in the various sub-regions of Vela C. Methods We mapped the submillimetre (345 GHz) emission from vela C with LABOCA (beam size 19.2\", spatial resolution ~0.07 pc at 700 pc) at the APEX telescope. We used the clump-finding algorithm CuTEx to identify the compact submillimetre sources. We also used SIMBA (250 GHz) observations, and Herschel and WISE ancillary data. The association with WISE red sources allowed the protostellar and starless cores to be separated, whereas the Herschel dataset allowed the dust temperature to be derived for a fraction of cores. The protostellar and starless core mass functions (CMFs) were constructed following two different approaches, achieving a mass completeness limit of 3.7 Msun. Results We retrieved 549 submillimetre cores, 316 of which are starless and mostly gravitationally bound (therefore prestellar in nature). Both the protostellar and the starless CMFs are consistent with the shape of a Salpeter initial mass function in the high-mass part of the distribution. Clustering of cores at scales of 1--6 pc is also found, hinting at fractionation of magnetised, turbulent gas.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics B |2019-07-18",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Cosmology And Nongalactic Astrophysics</center> \n <hr> \n\n### [Generalized Brans-Dicke theories in light of evolving dark energy](http://arxiv.org/abs/1907.07667v1) (1907.07667v1)\n<i>Alex Zucca, Levon Pogosian, Alessandra Silvestri, Yuting Wang, Gong-Bo Zhao</b>\n\n<h10>2019-07-17</h10>\n> The expansion history of the Universe reconstructed from a combination of recent data indicates a preference for a changing Dark Energy (DE) density. Moreover, the DE density appears to be increasing with cosmic time, with its equation of state being below -1 on average, and possibly crossing the so-called phantom divide. Scalar-tensor theories, in which the scalar field mediates a force between matter particles, offer a natural framework in which the effective DE equation of state can be less than -1 and cross the phantom barrier. We consider the generalized Brans-Dicke (GBD) class of scalar-tensor theories and reconstruct their Lagrangian given the effective DE density extracted from recent data. Then, given the reconstructed Lagrangian, we solve for the linear perturbations and investigate the characteristic signatures of these reconstructed GBD in the cosmological observables, such as the cosmic microwave background (CMB) anisotropy, the galaxy number counts, and their cross-correlations. In particular, we demonstrate that the Integrated Sachs-Wolfe (ISW) effect probed by the cross-correlation of CMB with the matter distribution can rule out scalar-tensor theories as the explanation of the observed DE dynamics independently from the laboratory and solar system fifth force constraints.\n\n### [Stellar cooling anomalies and variant axion models](http://arxiv.org/abs/1907.07662v1) (1907.07662v1)\n<i>Ken'ichi Saikawa, Tsutomu T. Yanagida</b>\n\n<h10>2019-07-17</h10>\n> A number of observations of stellar systems show a mild preference for anomalously fast cooling compared with what predicted in the standard theory, which leads to a speculation that there exists an additional energy loss mechanism originated from the emission of axions in stars. We explore the possibility that such excessive energy losses are interpreted in the framework of variant axion models, which require two Higgs doublets and flavor-dependent Peccei-Quinn charge assignments. These models resolve two fundamental issues faced in the traditional KSVZ/DFSZ models by predicting a sizable axion coupling to electrons required to explain the cooling anomalies and at the same time providing a solution to the cosmological domain wall problem. We also find that a specific structure of the axion couplings to electrons and nucleons slightly relaxes the constraint from supernova 1987A and enlarges viable parameter regions compared with the DFSZ models. It is shown that good global fits to the observational data are obtained for axion mass ranges of ![](http://latex2png.com/output//latex_f021ef1d14b6324d6a50e685c1f3d287.png), and that the predicted parameter regions can be probed in the forthcoming helioscope searches.\n\n### [Testing a quintessence model with Yukawa interaction from cosmological  observations and N-body simulations](http://arxiv.org/abs/1809.03224v2) (1809.03224v2)\n<i>Rui An, André A. Costa, Linfeng Xiao, Jiajun Zhang, Bin Wang</b>\n\n<h10>2018-09-10</h10>\n> We consider a quintessence model with Yukawa interaction between dark energy and dark matter and constrain this model by employing the recent cosmological data including the updated cosmic microwave background (CMB) measurements from Planck 2015, the weak gravitational lensing measurements from Kilo Degree Survey (KiDS) and redshift-space distortions. We find that an interaction in the dark sector is compatible with observations. The updated Planck data can significantly improve the constraints compared with the previous results from Planck 2013, while the KiDS data has less constraining power than Planck. The Yukawa interaction model is found to be moderately favored by Planck and able to alleviate the discordance between weak lensing measurements and CMB measurements as previously inferred from the standard Lambda cold dark matter model. N-body simulations for Yukawa interaction model is also performed. We find that using the halo density profile is plausible to improve the constraints significantly in the future.\n\n### [Entanglement entropy of Primordial Black Holes after inflation](http://arxiv.org/abs/1907.07601v1) (1907.07601v1)\n<i>Llorenç Espinosa-Portalés, Juan García-Bellido</b>\n\n<h10>2019-07-17</h10>\n> In this paper we study the survival of entanglement of a scalar field state created during inflation. We find that there exist UV-finite subdominant contributions to the entanglement entropy per momentum mode that scale with the number of e-folds between horizon exit and the end of inflation, and depend on the logarithm of the radius of the entangling surface, which can be taken to be the horizon sphere. We argue that this entanglement entropy allows for the formation of entangled Primordial Black Holes (PBH). We find that the entropy arising from the entanglement between PBH is small compared with their Bekenstein entropy.\n\n### [Correlations in the matter distribution in CLASH galaxy clusters](http://arxiv.org/abs/1808.02136v2) (1808.02136v2)\n<i>Antonino Del Popolo, Morgan Le Delliou, Xiguo Lee</b>\n\n<h10>2018-08-06</h10>\n> We study the total and dark matter (DM) density profiles as well as their correlations for a sample of 15 high-mass galaxy clusters by extending our previous work on several clusters from Newman et al. Our analysis focuses on 15 CLASH X-ray-selected clusters that have high-quality weak- and strong-lensing measurements from combined Subaru and {\\em Hubble Space Telescope} observations. The total density profiles derived from lensing are interpreted based on the two-phase scenario of cluster formation. In this context, the brightest cluster galaxy (BCG) forms in the first dissipative phase, followed by a dissipationless phase where baryonic physics flattens the inner DM distribution. This results in the formation of clusters with modified DM distribution and several correlations between characteristic quantities of the clusters. We find that the central DM density profiles of the clusters are strongly influenced by baryonic physics as found in our earlier work. The inner slope of the DM density for the CLASH clusters is found to be flatter than the Navarro--Frenk--White profile, ranging from ![](http://latex2png.com/output//latex_1e53fb4e9c07f5230adc15ddb0b4f9b4.png) to ![](http://latex2png.com/output//latex_5328a541d1538725427430270e4659cf.png). We examine correlations of the DM density slope ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png) with the effective radius ![](http://latex2png.com/output//latex_2be67ce534e8daaa5dfd30f0285ee748.png) and stellar mass ![](http://latex2png.com/output//latex_57a9618241a957130d8df325a255d300.png) of the BCG, finding that these quantities are anti-correlated with a Spearman correlation coefficient of ![](http://latex2png.com/output//latex_7f68151cffc9eb80c5b7ae9a0ab0b953.png). We also study the correlation between ![](http://latex2png.com/output//latex_2be67ce534e8daaa5dfd30f0285ee748.png) and the cluster halo mass ![](http://latex2png.com/output//latex_f1667e26dfb2c94f96534a4f2f511c88.png), and the correlation between the total masses inside 5\\,kpc and 100\\,kpc. We find that these quantities are correlated with Spearman coefficients of ![](http://latex2png.com/output//latex_d3b4da10b675f68cc20a4d128bd0d572.png) and ![](http://latex2png.com/output//latex_2201c0f1c8daec857ca146222b240694.png), respectively. These observed correlations are in support of the physical picture proposed by Newman et al.\n\n# <center>High Energy Astrophysical Phenomena</center> \n <hr> \n\n### [Signatures for quark matter from multi-messenger observations](http://arxiv.org/abs/1904.05471v3) (1904.05471v3)\n<i>Mark G. Alford, Sophia Han, Kai Schwenzer</b>\n\n<h10>2019-04-10</h10>\n> We review the prospects for detecting quark matter in neutron star cores. We survey the proposed signatures and emphasize the importance of data from neutron star mergers, which provide access to dynamical properties that operate on short timescales that are not probed by other neutron star observables.\n\n### [Accelerating the search for Axion-Like Particles with machine learning](http://arxiv.org/abs/1907.07642v1) (1907.07642v1)\n<i>Francesca Day, Sven Krippendorf</b>\n\n<h10>2019-07-17</h10>\n> Machine learning (ML) techniques have been applied with tremendous success in many areas of physics. In this work, we use ML to place bounds on the coupling between photons and axion-like particles (ALPs). This coupling causes ALPs and photons to interconvert in the presence of a background magnetic field. This would lead to modulations in the spectra of point sources shining through the magnetic fields of galaxy clusters. This effect has already been used to place world-leading bounds on the ALP-photon coupling using conventional statistical methods. We train ML classification algorithms on simulated spectra from the Chandra X-ray telescope for a range of point sources and ALP-photon couplings. We then use the response of these algorithms to the real Chandra spectra to place bounds on ALP-photon interactions. We obtain bounds at a similar level to those based on other techniques, but find improvements on an individual source basis. We expect such search techniques to become increasingly important for ALP searches with future telescopes that will offer substantially higher energy resolution.\n\n### [Gamma-ray burst jet propagation, development of angular structure, and  the luminosity function](http://arxiv.org/abs/1907.07599v1) (1907.07599v1)\n<i>O. S. Salafia, C. Barbieri, S. Ascenzi, M. Toffano</b>\n\n<h10>2019-07-17</h10>\n> The fate and observable properties of gamma-ray burst jets depend crucially on their interaction with the progenitor material that surrounds the central engine. We present a semi-analytical model of such interaction, which builds upon several previous analytical and numerical works, aimed at predicting the angular distribution of jet and cocoon energy and Lorentz factor after breakout, given the properties of the ambient material and of the jet at launch. Using this model, we construct synthetic populations of structured jets, assuming either a collapsar (for long gamma-ray bursts -- LGRBs) or a binary neutron star merger (for short gamma-ray bursts -- SGRBs) as progenitor. We assume all progenitors to be identical, and we allow little variability in the jet properties at launch: our populations therefore feature a quasi-universal structure. These populations are able to reproduce the main features of the observed LGRB and SGRB luminosity functions, although several uncertainties and caveats remain to be addressed.\n\n### [The physics of Weibel-mediated relativistic collisionless shocks](http://arxiv.org/abs/1907.07595v1) (1907.07595v1)\n<i>M. Lemoine, L. Gremillet, G. Pelletier, A. Vanthieghem</b>\n\n<h10>2019-07-17</h10>\n> We develop a comprehensive theoretical model of relativistic collisionless pair shocks mediated by the current filamentation instability. We notably characterize the noninertial frame in which this instability is of a mostly magnetic nature, and describe at a microscopic level the deceleration and heating of the incoming background plasma through its collisionless interaction with the electromagnetic turbulence. Our model compares well to large-scale 2D3V PIC simulations, and provides an important touchstone for the phenomenology of such plasma systems.\n\n### [The Transient program of the Cherenkov Telescope Array](http://arxiv.org/abs/1907.07567v1) (1907.07567v1)\n<i>Fabian Schüssler</b>\n\n<h10>2019-07-17</h10>\n> The Cherenkov Telescope Array (CTA) is the next generation high-energy gamma-ray observatory. It will improve the sensitivity of current instruments up to an order of magnitude, while providing energy coverage for photons from 20 GeV to at least 300 TeV to reach high redshifts and extreme accelerators and will give access to the shortest time-scale phenomena. CTA is thus a uniquely powerful instrument for the exploration of the violent and variable universe. The ability to probe short timescales at the highest energies will allow CTA to explore the connection between accretion and ejection phenomena surrounding compact objects, investigate the processes occurring in relativistic outflows, and open up significant phase space for serendipitous discoveries. Aiming at playing a central role in the era of multi-messenger astrophysics, the CTA Transient program includes follow-up observations of a broad range of multi-wavelength and multi-messenger alerts, ranging from Galactic compact object binary systems to novel phenomena like Fast Radio Bursts. A promising case is that of gamma-ray bursts (GRBs), where CTA will for the first time enable high-statistics measurements above ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png) 10 GeV, probing new spectral components and shedding light on the physical processes at work in these systems. Dedicated programs searching for very-high-energy (VHE) gamma-ray counterparts to gravitational waves and high-energy neutrinos complete the CTA transients program. This contribution will introduce and outline the CTA Transients program. We will provide an overview of the various science topics and discuss the links to multi-messenger and multi-wavelength observations.\n\n# <center>Instrumentation And Methods In Astrophysics</center> \n <hr> \n\n### [The DSA-2000 -- A Radio Survey Camera](http://arxiv.org/abs/1907.07648v1) (1907.07648v1)\n<i>G. Hallinan, V. Ravi, S. Weinreb, J. Kocz, Y. Huang, D. P. Woody, J. Lamb, L. D'Addario, M. Catha, J. Shi, C. Law, S. R. Kulkarni, E. S. Phinney, M. W. Eastwood, K. L. Bouman, M. A. McLaughlin, S. M. Ransom, X. Siemens, J. M. Cordes, R. S. Lynch, D. L. Kaplan, S. Chatterjee, J. Lazio, A. Brazier, S. Bhatnagar, S. T. Myers, F. Walter, B. M. Gaensler</b>\n\n<h10>2019-07-17</h10>\n> We present the DSA-2000: a world-leading radio survey telescope and multi-messenger discovery engine for the next decade. The array will be the first true radio camera, outputting science-ready image data over the 0.7 - 2 GHz frequency range with a spatial resolution of 3.5 arcsec. With 2000 x 5 m dishes, the DSA-2000 will have an equivalent point-source sensitivity to SKA1-mid, but with ten times the survey speed. The DSA-2000 is envisaged as an all-sky survey instrument complementary to the ngVLA, and as a counterpart to the LSST (optical), SPHEREx (near-infrared) and SRG/eROSITA (X-ray) all-sky surveys. Over a five-year prime phase, the DSA-2000 will image the entire sky above declination -30 degrees every four months, detecting > 1 unique billion radio sources in a combined full-Stokes sky map with 500 nJy/beam rms noise. This all-sky survey will be complemented by intermediate and deep surveys, as well as spectral and polarization image cubes. The array will be a cornerstone for multi-messenger science, serving as the principal instrument for the US pulsar timing array community, and by searching for radio afterglows of compact object mergers detected by LIGO and Virgo. The array will simultaneously detect and localize ~10,000 fast radio bursts each year, realizing their ultimate use as a cosmological tool. The DSA-2000 will be proposed to the NSF Mid-Scale Research Infrastructure-2 program with a view to first light in 2026\n\n### [CubeSats for Astronomy and Astrophysics](http://arxiv.org/abs/1907.07634v1) (1907.07634v1)\n<i>Ewan S. Douglas, Kerri L. Cahoy, Mary Knapp, Rachel E. Morgan</b>\n\n<h10>2019-07-17</h10>\n> CubeSats have the potential to expand astrophysical discovery space, complementing ground-based electromagnetic and gravitational-wave observatories. The CubeSat design specifications help streamline delivery of instrument payloads to space. CubeSat planners have more options for tailoring orbits to fit observational needs and may have more flexibility in rapidly rescheduling observations to respond to transients. With over 1000 CubeSats launched, there has been a corresponding increase in the availability and performance of commercial-off-the-shelf (COTS) components compatible with the CubeSat standards, from solar panels and power systems to reaction wheels for three axis stabilization and precision attitude control. Commercially available components can reduce cost CubeSat missions, allowing more resources to be directed toward scientific instrument payload development and technology demonstrations.\n\n### [All-sky Medium Energy Gamma-ray Observatory: Exploring the Extreme  Multimessenger Universe](http://arxiv.org/abs/1907.07558v1) (1907.07558v1)\n<i>Julie McEnery, Juan Abel Barrio, Ivan Agudo, Marco Ajello, José-Manuel Álvarez, Stefano Ansoldi, Sonia Anton, Natalia Auricchio, John B. Stephen, Luca Baldini, Cosimo Bambi, Matthew Baring, Ulisses Barres, Denis Bastieri, John Beacom, Volker Beckmann, Wlodek Bednarek, Denis Bernard, Elisabetta Bissaldi, Peter Bloser, Harsha Blumer, Markus Boettcher, Steven Boggs, Aleksey Bolotnikov, Eugenio Bottacini, Vladimir Bozhilov, Enrico Bozzo, Michael Briggs, Jim Buckley, Sara Buson, Riccardo Campana, Regina Caputo, Martina Cardillo, Ezio Caroli, Daniel Castro, S. Brad Cenko, Eric Charles, Wenlei Chen, Teddy Cheung, Stefano Ciprini, Paolo Coppi, Rui Curado da Silva, Sara Cutini, Filippo D'Ammando, Alessandro De Angelis, Michaël De Becker, Georgia De Nolfo, Stefano Del Sordo, Mattia Di Mauro, Leonardo Di Venere, Stefano Dietrich, Seth Digel, Alberto Dominguez, Michele Doro, Elizabeth Ferrara, Brian Fields, Justin Finke, Luca Foffano, Chris Fryer, Yasushi Fukazawa, Stefan Funk, Dario Gasparrini, Joseph Gelfand, Markos Georganopoulos, Francesco Giordano, Andrea Giuliani, Christian Gouiffes, Brian Grefenstette, Isabelle Grenier, Sean Griffin, Eric Grove, Sylvain Guiriec, Alice Harding, Pat Harding, Dieter Hartmann, Elizabeth Hays, Margarita Hernanz, Jack Hewitt, Jamie Holder, Michelle Hui, Andrew Inglis, Robert Johnson, Sam Jones, Gottfried Kanbach, Oleg Kargaltsev, Sarah Kaufmann, Matthew Kerr, Carolyn Kierans, Fabian Kislat, Alexei V. Klimenko, Jurgen Knodlseder, Daniel Kocveski, Joachim Kopp, Henric Krawczynsiki, John Krizmanic, Hidetoshi Kubo, Naoko Kurahashi Neilson, Philippe Laurent, Jean-Philippe Lenain, Hui Li, Amy Lien, Tim Linden, Jan Lommler, Francesco Longo, Michael Lovellette, Marcos López, Antonios Manousakis, Lea Marcotulli, Alexandre Marcowith, Manel Martinez, Marc McConnell, Jessica Metcalfe, Eileen Meyer, Manuel Meyer, Roberto Mignani, John Mitchell, Tsunefumi Mizuno, Alexander Moiseev, Daniel Morcuende, Igor Moskalenko, Michael Moss, Kazuhiro Nakazawa, M. Nicola Mazziotta, Uwe Oberlack, Masanori Ohno, Foteini Oikonomou, Roopesh Ojha, Nicola Omodei, Elena Orlando, Nepomuk Otte, Vaidehi S Paliya, Lucas Parker, Barbara Patricelli, Jeremy Perkins, Maria Petropoulou, Carlotta Pittori, Martin Pohl, Troy Porter, Elisa Prandini, Chanda Prescod-Weinstein, Judith Racusin, Riccardo Rando, Bindu Rani, Marc Ribó, James Rodi, Miguel A. Sanchez-Conde, Pablo Saz Parkinson, Richard Schirato, Peter Shawhan, Chris Shrader, Jacob Smith, Karl Smith, Antonio Stamerra, Lukasz Stawarz, Andy Strong, Inga Stumke, Hiro Tajima, Hiromitsu Takahashi, Yasuyuki Tanaka, Vincent Tatischeff, Lih-Sin The, David Thompson, Luigi Tibaldo, John Tomsick, Lucas Uhm, Tonia Venters, Tom Vestrand, Giacomo Vianello, Zorawar Wadiasingh, Roland Walter, Xilu Wang, David Williams, Colleen Wilson-Hodge, Matthew Wood, Richard Woolf, Eric Wulf, George Younes, Luca Zampieri, Silvia Zane, Bing Zhang, Haocheng Zhang, Stephan Zimmer, Andreas Zoglauer, Alexander van der Horst</b>\n\n<h10>2019-07-17</h10>\n> The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity in the 200 keV to 10 GeV energy range with a wide field of view, good spectral resolution, and polarization sensitivity. Therefore, AMEGO is key in the study of multimessenger astrophysical objects that have unique signatures in the gamma-ray regime, such as neutron star mergers, supernovae, and flaring active galactic nuclei. The order-of-magnitude improvement compared to previous MeV missions also enables discoveries of a wide range of phenomena whose energy output peaks in the relatively unexplored medium-energy gamma-ray band.\n\n### [Monte Carlo Studies of Combined MAGIC and LST1 Observations](http://arxiv.org/abs/1907.07508v1) (1907.07508v1)\n<i>F. Di Pierro, L. Arrabito, A. Baquero Larriva, A. Berti, J. Bregeon, D. Depaoli, D. Dominis Prester, R. Lopez Coto, M. Manganaro, S. Mićanović, A. Moralejo, Y. Ohtani, L. Saha, J. Sitarek, Y. Suda, T. Terzić, I. Vovk, T. Vuillaume</b>\n\n<h10>2019-07-17</h10>\n> The Cherenkov Telescope Array (CTA) is the next generation very high energy gamma-ray observatory covering the 20 GeV - 300 TeV energy range with unprecedented sensitivity, angular and energy resolution. With a site in each hemisphere, CTA will provide full-sky coverage. Four Large Size Telescopes (LSTs) in each site will be dedicated to the lowest energy range (20 GeV - 200 GeV). The first LST prototype has been installed at the CTA Northern site (Canary Island of La Palma, Spain) in October 2018 and it had been since then in commissioning phase. LST1 is located at about 100 m from MAGIC, a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes designed to perform gamma-ray astronomy in the energy range from 50 GeV with standard trigger (30 GeV with SumTrigger) to 50 TeV and whose performance is very well established. The co-location of LST1 and MAGIC offers the great opportunity of cross-calibrating the two systems on an event-by-event basis. It will be indeed possible to compare the parameters of the same extensive air shower reconstructed by the two instruments. We investigated the performance that could be reached with combined observations.\n\n### [Entropy Symmetrization and High-Order Accurate Entropy Stable Numerical  Schemes for Relativistic MHD Equations](http://arxiv.org/abs/1907.07467v1) (1907.07467v1)\n<i>Kailiang Wu, Chi-Wang Shu</b>\n\n<h10>2019-07-17</h10>\n> This paper presents entropy symmetrization and high-order accurate entropy stable schemes for the relativistic magnetohydrodynamic (RMHD) equations. It is shown that the conservative RMHD equations are not symmetrizable and do not possess an entropy pair. To address this issue, a symmetrizable RMHD system, which admits a convex entropy pair, is proposed by adding a source term into the equations. Arbitrarily high-order accurate entropy stable finite difference schemes are then developed on Cartesian meshes based on the symmetrizable RMHD system. The crucial ingredients of these schemes include (i) affordable explicit entropy conservative fluxes which are technically derived through carefully selected parameter variables, (ii) a special high-order discretization of the source term in the symmetrizable RMHD system, and (iii) suitable high-order dissipative operators based on essentially non-oscillatory reconstruction to ensure the entropy stability. Several benchmark numerical tests demonstrate the accuracy and robustness of the proposed entropy stable schemes of the symmetrizable RMHD equations.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics A |2019-07-18",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Astrophysics Of Galaxies</center> \n <hr> \n\n### [Discovery of a very hot phase of the Milky Way CGM with non-solar  abundance ratios](http://arxiv.org/abs/1907.07176v1) (1907.07176v1)\n<i>Sanskriti Das, Smita mathur, Fabrizio Nicastro, Yair Krongold</b>\n\n<h10>2019-07-16</h10>\n> We present the discovery of a very hot gas phase of the Milky Way circumgalactic medium (CGM) at T ![](http://latex2png.com/output//latex_c2afdda196cd14f0e333ab4bf53c2741.png) K, using deep XMM-Newton RGS observations of 1ES 1553+113. The hot gas, coexisting with a warm-hot phase at T ![](http://latex2png.com/output//latex_471a60bb2d2e8b554aa428bc53aeefc5.png) K is ![](http://latex2png.com/output//latex_7ec85b34a490aea8e2f9acf6dcc7a791.png)enhanced, with [O/Fe] = 0.9![](http://latex2png.com/output//latex_51a81fc56ef9976b6f05d09718e6951d.png), indicating core-collapse supernovae enrichment. Additionally we find [Ne/O] and [N/O] = ![](http://latex2png.com/output//latex_4fca3ccc6fd13b5bb301fd6107027336.png), such that N/Ne is consistent with solar. Along with the enrichment by AGB stars and core-collapse supernovae, this indicates that some Oxygen has depleted onto dust and/or transited to cooler gas phase(s). These results may affect previous baryonic and metallic mass estimations of the warm-hot and hot CGM from the observations of Oxygen emission and absorption. Our results provide insights on the heating, mixing and chemical enrichment of the Milky Way CGM, and provide inputs to theoretical models of galaxy evolution.\n\n### [ALMA Detection of Vibrationally Excited (![](http://latex2png.com/output//latex_cc14f2302d9e49a54a5e091bdf57a936.png)) Acetic  Acid toward NGC 6334I](http://arxiv.org/abs/1907.07117v1) (1907.07117v1)\n<i>Ci Xue, Anthony J. Remijan, Crystal L. Brogan, Todd R. Hunter, Eric Herbst, Brett A. McGuire</b>\n\n<h10>2019-07-16</h10>\n> Vibrationally excited states of detected interstellar molecules have been shown to account for a large portion of unidentified spectral lines in observed interstellar spectra toward chemically rich sources. Here, we present the first interstellar detection of the first and second vibrationally excited torsional states of acetic acid (![](http://latex2png.com/output//latex_06c6efe909bfc30c6f7f3085c8ebfb03.png)) toward the high-mass star-forming region NGC 6334I. The observations presented were taken with the Atacama Large Millimeter/submillimeter Array in bands 4, 6, and 7 covering a frequency range of 130 - 352 GHz. By comparing a single excitation temperature model to the observations, the best-fit excitation temperature and column density are obtained to be 142(25) K and ![](http://latex2png.com/output//latex_d700a9961752e38561746697258f85dd.png) respectively. Based on the intensity maps of the vibrationally excited CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)COOH transitions, we found that the CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)COOH emissions are compact and concentrated toward the MM1 and MM2 regions with a source size smaller than 2 arcsec. After locating the emission from different CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)COOH transitions, which cover a large range of excitation energies, we are able to explain the variation of the CH![](http://latex2png.com/output//latex_ceb601cfa46671c9d5f89605cccc2ec9.png)COOH emission peak within the MM2 core by invoking continuum absorption or outflows.\n\n### [Warped diffusive radio halo around the quiescent spiral edge-on galaxy  NGC 4565](http://arxiv.org/abs/1907.07076v1) (1907.07076v1)\n<i>V. Heesen, L. Whitler, P. Schmidt, A. Miskolczi, S. S. Sridhar, C. Horellou, R. Beck, G. Gürkan, E. Scannapieco, M. Brüggen, G. H. Heald, M. Krause, R. Paladino, B. Nikiel-Wroczyński, R. -J. Dettmar</b>\n\n<h10>2019-07-16</h10>\n> Cosmic rays play a pivotal role in launching galactic winds, particularly in quiescently star-forming galaxies where the hot gas alone is not sufficient to drive a wind. Except for the Milky Way, not much is known about the transport of cosmic rays in galaxies. In this Letter, we present low-frequency observations of the nearby edge-on spiral galaxy NGC 4565 using the LOw-Frequency ARray (LOFAR). With our deep 144-MHz observations, we obtain a clean estimate of the emission originating from old cosmic-ray electrons (CRe), which is almost free from contamination by thermal emission. We measured vertical profiles of the non-thermal radio continuum emission that we fitted with Gaussian and exponential functions. The different profile shapes correspond to 1D cosmic-ray transport models of pure diffusion and advection, respectively. We detect a warp in the radio continuum that is reminiscent of the previously known HI warp. Because the warp is not seen at GHz-frequencies in the radio continuum, its minimum age must be about 100 Myr. The warp also explains the slight flaring of the thick radio disc that can otherwise be well described by a Gaussian profile with an FWHM of 65 arcsec (3.7 kpc). The diffusive radio halo together with the extra-planar X-ray emission may be remnants of enhanced star-forming activity in the past where the galaxy had a galactic wind, as GHz-observations indicate only a weak outflow in the last 40 Myr. NGC 4565 could be in transition from an outflow- to an inflow-dominated phase.\n\n### [Spectral analysis of the hybrid PG 1159-type central stars of the  planetary nebulae Abell 43 and NGC 7094](http://arxiv.org/abs/1907.07049v1) (1907.07049v1)\n<i>L. Löbling, T. Rauch, M. M. Miller Bertolami, H. Todt, F. Friederich, M. Ziegler, K. Werner, J. W. Kruk</b>\n\n<h10>2019-07-16</h10>\n> Stellar post asymptotic giant branch (post-AGB) evolution can be completely altered by a final thermal pulse (FTP) which may occur when the star is still leaving the AGB (AFTP), at the departure from the AGB at still constant luminosity (late TP, LTP) or after the entry to the white-dwarf cooling sequence (very late TP, VLTP). Then convection mixes the He-rich material with the H-rich envelope. According to stellar evolution models the result is a star with a surface composition of ![](http://latex2png.com/output//latex_be266cdb813d56beddcbca39985cb6c5.png)% by mass (AFTP), ![](http://latex2png.com/output//latex_ee4b3d49f95ce5f908656f7d61e531c6.png)% (LTP), or (almost) no H (VLTP). Since FTP stars exhibit intershell material at their surface, spectral analyses establish constraints for AGB nucleosynthesis and stellar evolution. We performed a spectral analysis of the so-called hybrid PG 1159-type central stars (CS) of the planetary nebulae Abell 43 and NGC7094 by means of non-local thermodynamical equilibrium models. We confirm the previously determined effective temperatures of ![](http://latex2png.com/output//latex_77e2e426885fb860552b77260b18d1d1.png)K and determine surface gravities of ![](http://latex2png.com/output//latex_a567f6bba122518d61c26b2dcf1a5f2b.png) for both. From a comparison with AFTP evolutionary tracks, we derive stellar masses of ![](http://latex2png.com/output//latex_4b442d7257cafb151da335d0de8464cc.png) and determine the abundances of H, He, and metals up to Xe. Both CS are likely AFTP stars with a surface H mass fraction of ![](http://latex2png.com/output//latex_6c55b3f9a0164b135e8d8eea13b00e0e.png) and ![](http://latex2png.com/output//latex_7ef12f499d9aa9c91a6aa72332c0c5d0.png), respectively, and a Fe deficiency indicating subsolar initial metallicities. The light metals show typical PG 1159-type abundances and the elemental composition is in good agreement with predictions from AFTP evolutionary models. However, the expansion ages do not agree with evolution timescales expected from the AFTP scenario and alternatives should be explored.\n\n### [The nature of the soft-excess and spectral variability in the Seyfert 1  galaxy Zw 229.015](http://arxiv.org/abs/1907.07048v1) (1907.07048v1)\n<i>S. Tripathi, S. G. H. Waddell, L. C. Gallo, W. F. Welsh, C-Y. Chiang</b>\n\n<h10>2019-07-16</h10>\n> We have carried out a systematic analysis of the nearby (z=0.0279) active galaxy Zw 229.015 using multi-epoch, multi-instrument and deep pointed observations with XMM-Newton, Suzaku, Swift and NuSTAR. Spectral and temporal variability are examined in detail on both the long (weeks-to-years) and short (hours) timescales. A deep Suzaku observation of the source shows two distinct spectral states; a bright-soft state and a dim-hard state in which changes in the power law component account for the differences. Partial covering, blurred reflection and soft Comptonisation models describe the X-ray spectra comparably well, but the smooth, rather featureless, spectrum may be favouring the soft Comptonisation scenario. Moreover, independent of the spectral model, the observed spectral variability is ascribed to the changes in the power law continuum only and do not require changes in the properties of the absorber or blurred reflector incorporated in the other scenarios. The multi-epoch observations between 2009 and 2018 can be described in similar fashion. This could be understood if the primary emission is originating at a large distance from a standard accretion disc or if the disc is optically thin and geometrically thick as recently proposed for Zw 229.015. Our investigation shows that Zw 229.015 behaves similar to sources like Akn 120 and Mrk 530, that exhibit a strong soft-excess, but weak Compton hump and Fe K![](http://latex2png.com/output//latex_966896c8577c51b07260186d88ec1004.png) emission.\n\n# <center>Earth And Planetary Astrophysics</center> \n <hr> \n\n### [Atmospheric Electricity at the Ice Giants](http://arxiv.org/abs/1907.07151v1) (1907.07151v1)\n<i>K. L. Aplin, G. Fischer, T. A. Nordheim, A. Konovalenko, V. Zakharenko, P. Zarka</b>\n\n<h10>2019-07-16</h10>\n> Lightning was detected by Voyager 2 at Uranus and Neptune, and weaker electrical processes also occur throughout planetary atmospheres from galactic cosmic ray (GCR) ionisation. Lightning is an indicator of convection, whereas electrical processes away from storms modulate cloud formation and chemistry, particularly if there is little insolation to drive other mechanisms. The ice giants appear to be unique in the Solar System in that they are distant enough from the Sun for GCR-related mechanisms to be significant for clouds and climate, yet also convective enough for lightning to occur. This paper reviews observations (both from Voyager 2 and Earth), data analysis and modelling, and considers options for future missions. Radio, energetic particle and magnetic instruments are recommended for future orbiters, and Huygens-like atmospheric electricity sensors for in situ observations. Uranian lightning is also expected to be detectable from terrestrial radio telescopes.\n\n### [An emission spectrum for WASP-121b measured across the 0.8-1.1 micron  wavelength range using the Hubble Space Telescope](http://arxiv.org/abs/1906.06326v2) (1906.06326v2)\n<i>Thomas Mikal-Evans, David K. Sing, Jayesh M. Goyal, Benjamin Drummond, Aarynn L. Carter, Gregory W. Henry, Hannah R. Wakeford, Nikole K. Lewis, Mark S. Marley, Pascal Tremblin, Nikolay Nikolov, Tiffany Kataria, Drake Deming, Gilda E. Ballester</b>\n\n<h10>2019-06-14</h10>\n> WASP-121b is a transiting gas giant exoplanet orbiting close to its Roche limit, with an inflated radius nearly double that of Jupiter and a dayside temperature comparable to a late M dwarf photosphere. Secondary eclipse observations covering the 1.1-1.6 micron wavelength range have revealed an atmospheric thermal inversion on the dayside hemisphere, likely caused by high altitude absorption at optical wavelengths. Here we present secondary eclipse observations made with the Hubble Space Telescope Wide Field Camera 3 spectrograph that extend the wavelength coverage from 1.1 micron down to 0.8 micron. To determine the atmospheric properties from the measured eclipse spectrum, we performed a retrieval analysis assuming chemical equilibrium, with the effects of thermal dissociation and ionization included. Our best-fit model provides a good fit to the data with reduced chi^2=1.04. The data diverge from a blackbody spectrum and instead exhibit emission due to H- shortward of 1.1 micron. The best-fit model does not reproduce a previously reported bump in the spectrum at 1.25 micron, possibly indicating this feature is a statistical fluctuation in the data rather than a VO emission band as had been tentatively suggested. We estimate an atmospheric metallicity of [M/H]=1.09(-0.69,+0.57), and fit for the carbon and oxygen abundances separately, obtaining [C/H]=-0.29(-0.48,+0.61) and [O/H]=0.18(-0.60,+0.64). The corresponding carbon-to-oxygen ratio is C/O=0.49(-0.37,+0.65), which encompasses the solar value of 0.54, but has a large uncertainty.\n\n### [Occultation observations of Saturn's rings with Cassini VIMS](http://arxiv.org/abs/1907.06980v1) (1907.06980v1)\n<i>P. D. Nicholson, T. Ansty, M. M. Hedman, D. Creel, J. Ahlers, R. A. Harbison, R. H. Brown, R. N. Clark, K. H. Baines, B. J. Buratti, C. Sotin, S. V. Badman</b>\n\n<h10>2019-07-16</h10>\n> We describe the prediction, design, execution and calibration of stellar and solar occultation observations of Saturn's rings by the Visual and Infrared Mapping Spectrometer (VIMS) instrument on the Cassini spacecraft. Particular attention is paid to the technique developed for onboard acquisition of the stellar target and to the geometric and photometric calibration of the data. Examples of both stellar and solar occultation data are presented, highlighting several aspects of the data as well as the different occultation geometries encountered during Cassini's 13 year orbital tour. Complete catalogs of ring stellar and solar occultations observed by Cassini-VIMS are presented, as a guide to the standard data sets which have been delivered to the Planetary Data System's Ring Moon Systems Node.\n\n### [Astro2020 APC White Paper: Durable Agency Support for Exoplanet Catalogs  and Archives](http://arxiv.org/abs/1907.06977v1) (1907.06977v1)\n<i>Joshua Pepper, David Ciardi, Todd Henry, Susan Mullally</b>\n\n<h10>2019-07-16</h10>\n> Many projects in current exoplanet science make use of catalogs of known exoplanets and their host stars. These may be used for demographic, population, and statistical studies, or for identifying targets for future observations. The ability to efficiently and accurately conduct exoplanet science depends on the completeness, accuracy, and access to these catalogs. In this white paper, we argue that long-term agency support and maintenance of exoplanet archives is of crucial importance to achieving the scientific goals of the community and the strategic goals of the funding agencies. As such, it is imperative that these facilities are appropriately supported and maintained by the national funding agencies.\n\n### [Stable attitude dynamics of planar helio-stable and drag-stable sails](http://arxiv.org/abs/1907.06908v1) (1907.06908v1)\n<i>Narcís Miguel, Camilla Colombo</b>\n\n<h10>2019-07-16</h10>\n> In this paper the planar orbit and attitude dynamics of an uncontrolled spacecraft is studied, taking on-board a deorbiting device. Solar and drag sails with the same shape are considered and separately studied. In both cases, these devices are assumed to have a simplified pyramidal shape that endows the spacecraft with helio and drag stable properties. The translational dynamics is assumed to be planar and hence the rotational dynamics occurs only around one of the principal axes of the spacecraft. Stable or slowly-varying attitudes are studied, subject to disturbances due to the Earth oblateness effect and gravity gradient torques, and either solar radiation pressure or atmospheric drag torque and acceleration. The results are analysed with respect to the aperture of the sail and the center of mass - center of pressure offset.\n\n# <center>Solar And Stellar Astrophysics</center> \n <hr> \n\n### [3D MHD simulations and synthetic radio emission from an oblique rotating  magnetic massive star](http://arxiv.org/abs/1907.07068v1) (1907.07068v1)\n<i>Simon Daley-Yates, Ian R. Stevens, Asif ud-Doula</b>\n\n<h10>2019-07-16</h10>\n> We have performed 3D isothermal MHD simulation of a magnetic rotating massive star with a non-zero dipole obliquity and predicted the radio/sub-mm observable lightcurves and continuum spectra for a frequency range compatible with ALMA. From these results we also compare the model input mass-loss to that calculated from the synthetic thermal emission. Spherical and cylindrical symmetry is broken due to the obliquity of the stellar magnetic dipole resulting in an inclination and phase dependence of both the spectral flux and inferred mass-loss rate, providing testable predictions of variability for oblique rotator. Both quantities vary by factors between 2 and 3 over a full rotational period of the star, demonstrating that the role of rotation as critical in understanding the emission. This illustrates the divergence from a symmetric wind, resulting in a two armed spiral structure indicative of a oblique magnetic rotator. We show that a constant spectral index, ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png), model agrees well with our numerical prediction for a spherical wind for ![](http://latex2png.com/output//latex_92ace74d6703028689d8ff93f02c313a.png), however it is unable to capture the behavior of emission at ![](http://latex2png.com/output//latex_c2dd60a7bbce49d3beb1ec7943d30f60.png). As such we caution the use of such constant ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png) models for predicting emission from non-spherical winds such as those which form around magnetic massive stars.\n\n### [Damping of slow magnetoacoustic oscillations by the misbalance between  heating and cooling processes in the solar corona](http://arxiv.org/abs/1907.07051v1) (1907.07051v1)\n<i>D. Y. Kolotkov, V. M. Nakariakov, D. I. Zavershinskii</b>\n\n<h10>2019-07-16</h10>\n> Rapidly decaying slow magnetoacoustic waves are regularly observed in the solar coronal structures, offering a promising tool for a seismological diagnostics of the coronal plasma, including its thermodynamical properties. The effect of damping of standing slow magnetoacoustic oscillations in the solar coronal loops is investigated accounting for the field-aligned thermal conductivity and a wave-induced misbalance between radiative cooling and some unspecified heating rates. The non-adiabatic terms were allowed to be arbitrarily large, corresponding to the observed values. The thermal conductivity was taken in its classical form, and a power-law dependence of the heating function on the density and temperature was assumed. The analysis was conducted in the linear regime and in the infinite magnetic field approximation. The wave dynamics is found to be highly sensitive to the characteristic time scales of the thermal misbalance. Depending on certain values of the misbalance time scales three regimes of the wave evolution were identified, namely the regime of a suppressed damping, enhanced damping where the damping rate drops down to the observational values, and acoustic over-stability. The specific regime is determined by the dependences of the radiative cooling and heating functions on thermodynamical parameters of the plasma in the vicinity of the perturbed thermal equilibrium. The comparison of the observed and theoretically derived decay times and oscillation periods allows us to constrain the coronal heating function. For typical coronal parameters, the observed properties of standing slow magnetoacoustic oscillations could be readily reproduced with a reasonable choice of the heating function.\n\n### [Spectral analysis of the hybrid PG 1159-type central stars of the  planetary nebulae Abell 43 and NGC 7094](http://arxiv.org/abs/1907.07049v1) (1907.07049v1)\n<i>L. Löbling, T. Rauch, M. M. Miller Bertolami, H. Todt, F. Friederich, M. Ziegler, K. Werner, J. W. Kruk</b>\n\n<h10>2019-07-16</h10>\n> Stellar post asymptotic giant branch (post-AGB) evolution can be completely altered by a final thermal pulse (FTP) which may occur when the star is still leaving the AGB (AFTP), at the departure from the AGB at still constant luminosity (late TP, LTP) or after the entry to the white-dwarf cooling sequence (very late TP, VLTP). Then convection mixes the He-rich material with the H-rich envelope. According to stellar evolution models the result is a star with a surface composition of ![](http://latex2png.com/output//latex_be266cdb813d56beddcbca39985cb6c5.png)% by mass (AFTP), ![](http://latex2png.com/output//latex_ee4b3d49f95ce5f908656f7d61e531c6.png)% (LTP), or (almost) no H (VLTP). Since FTP stars exhibit intershell material at their surface, spectral analyses establish constraints for AGB nucleosynthesis and stellar evolution. We performed a spectral analysis of the so-called hybrid PG 1159-type central stars (CS) of the planetary nebulae Abell 43 and NGC7094 by means of non-local thermodynamical equilibrium models. We confirm the previously determined effective temperatures of ![](http://latex2png.com/output//latex_77e2e426885fb860552b77260b18d1d1.png)K and determine surface gravities of ![](http://latex2png.com/output//latex_a567f6bba122518d61c26b2dcf1a5f2b.png) for both. From a comparison with AFTP evolutionary tracks, we derive stellar masses of ![](http://latex2png.com/output//latex_4b442d7257cafb151da335d0de8464cc.png) and determine the abundances of H, He, and metals up to Xe. Both CS are likely AFTP stars with a surface H mass fraction of ![](http://latex2png.com/output//latex_6c55b3f9a0164b135e8d8eea13b00e0e.png) and ![](http://latex2png.com/output//latex_7ef12f499d9aa9c91a6aa72332c0c5d0.png), respectively, and a Fe deficiency indicating subsolar initial metallicities. The light metals show typical PG 1159-type abundances and the elemental composition is in good agreement with predictions from AFTP evolutionary models. However, the expansion ages do not agree with evolution timescales expected from the AFTP scenario and alternatives should be explored.\n\n### [CO~(![](http://latex2png.com/output//latex_cdf708904a7871a7feb5dc9684bc5e37.png)) Observations toward Filamentary Molecular Clouds in the  Galactic Region with ![](http://latex2png.com/output//latex_8f68bd6e894e74c9d39342086a693525.png)](http://arxiv.org/abs/1907.06973v1) (1907.06973v1)\n<i>Fang Xiong, Xuepeng Chen, Qizhou Zhang, Ji Yang, Min Fang, Miaomiao Zhang, Weihua Guo, Li Sun</b>\n\n<h10>2019-07-16</h10>\n> We present observations of the CO isotopologues (![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)CO, ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CO, and C![](http://latex2png.com/output//latex_6a51c1fc457445303f85476d62118c55.png)O) toward the Galactic region with ![](http://latex2png.com/output//latex_e040823d906506f2f74299a2af380afc.png) and ![](http://latex2png.com/output//latex_ce24a5e5fdb5612c4bc09b33d6cb503a.png), using the Purple Mountain Observatory 13.7~m millimeter-wavelength telescope. Based on the ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CO~(![](http://latex2png.com/output//latex_3f7f889b4127552c5b54e2eab2056182.png)) data, we find five molecular clouds within the velocity range between ![](http://latex2png.com/output//latex_e074429016e6d1a368941d0500f477b2.png)25 and 8~km~s![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png) that are all characterized by conspicuous filamentary structures. We have identified eight filaments with a length of 6.38--28.45~pc, a mean H![](http://latex2png.com/output//latex_4223ec05912b994c2067ff9b6a5e0098.png) column density of 0.70![](http://latex2png.com/output//latex_9bb371b028aa239acb1b8bb6ea62dcaf.png)10![](http://latex2png.com/output//latex_1c1c589a91f2f7940af56162045ce1bb.png)--6.53![](http://latex2png.com/output//latex_9bb371b028aa239acb1b8bb6ea62dcaf.png)10![](http://latex2png.com/output//latex_1c1c589a91f2f7940af56162045ce1bb.png)~cm![](http://latex2png.com/output//latex_db4c3014f85c291056b20e1646758c09.png), and a line mass of 20.24--161.91~![](http://latex2png.com/output//latex_00d25e382c5ba3238bf790298e0233f1.png) pc![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png), assuming a distance of ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)1.7~kpc. Gaussian fittings to the inner parts of the radial density profiles lead to a mean FWHM width of 1.13![](http://latex2png.com/output//latex_174ac781ee40ce7c1db4f55851bbbc24.png)0.01~pc. The velocity structures of most filaments present continuous distributions with slight velocity gradients. We find that turbulence is the dominant internal pressure to support the fragmentation of filaments instead of thermal pressure. Most filaments have virial parameters smaller than 2; thus, they are gravitationally bound. Four filaments have an LTE line mass close to the virial line mass. We further extract dense clumps using the ![](http://latex2png.com/output//latex_5874242198c9a54f3d6e102f3e3c3510.png)CO data and find that 64![](http://latex2png.com/output//latex_19e2197746f9513549591854d2287568.png) of the clumps are associated with the filaments. According to the complementary IR data, most filaments have associated Class~II young stellar objects. Class~I objects are mainly found to be located in the filaments with a virial parameter close to 1. Within two virialized filaments, ![](http://latex2png.com/output//latex_05caa7cb20262ce036fdbd9068c228c1.png)CO outflows have been detected, indicating ongoing star-forming activity therein.\n\n### [Acoustic wave generation in collapsing massive stars with convective  shells](http://arxiv.org/abs/1907.06966v1) (1907.06966v1)\n<i>Ernazar Abdikamalov, Thierry Foglizzo</b>\n\n<h10>2019-07-16</h10>\n> The convection that takes place in the innermost shells of massive stars plays an important role in the formation of core-collapse supernova explosions. Upon encountering the supernova shock, additional turbulence is generated, amplifying the explosion. In this work, we study how the convective perturbations evolve during the stellar collapse. Our main aim is to establish their physical properties right before they reach the supernova shock. To this end, we solve the linearized hydrodynamics equations perturbed on a stationary background flow. The latter is given by the spherical transonic Bondi accretion, while the convective perturbations are modeled as a combination of entropy and vorticity waves. We follow their evolution from large radii, where convective shells are initially located, down to small radii, where they are expected to encounter the accretion shock above the proto-neutron star. Considering typical vorticity perturbations with a Mach number ![](http://latex2png.com/output//latex_f70d7f6d03d77623e31cb12c0ad5a4e1.png) and entropy perturbations ![](http://latex2png.com/output//latex_cef27ba064b1b8915bf52301d0c34064.png) at a radius of ![](http://latex2png.com/output//latex_35206afa18ea6b33dcbf00eb9f526ecd.png), we find that the advection of these perturbations down to the shock generates strong acoustic waves with a relative amplitude ![](http://latex2png.com/output//latex_9cf11e876c9314bf1ea8dd8e15d49f84.png), in agreement with numerical simulations. The velocity perturbations consist of comparable contributions from vorticity and acoustic waves with values reaching ![](http://latex2png.com/output//latex_82a66d61aa1be63a56248f8a362d9ed6.png) of the sound speed ahead of the shock.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics B |2019-07-17",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Cosmology And Nongalactic Astrophysics</center> \n <hr> \n\n### [A natural ![](http://latex2png.com/output//latex_351ece7db9fa4c7051a1487afddf5215.png)-portal Majorana dark matter in alternative U(1)  extended Standard Model](http://arxiv.org/abs/1811.11927v3) (1811.11927v3)\n<i>Nobuchika Okada, Satomi Okada, Digesh Raut</b>\n\n<h10>2018-11-29</h10>\n> We consider a non-exotic gauged U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) extension of the Standard Model (SM), where the U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) charge of a SM field is given by a linear combination of its hypercharge and Baryon-minus-Lepton (![](http://latex2png.com/output//latex_ed873664075d7178715f4dfa0f89eb2d.png)) number. All the gauge and mixed gauge-gravitational anomalies are cancelled in this model with the introduction of three right-handed neutrinos (RHNs). Unlike the conventional minimal U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) model, where a universal U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) charge of ![](http://latex2png.com/output//latex_8ba88fa4936d18947c9ec63126d92abe.png) is assigned to three RHNs, we consider an alternative charge assignment, namely, two RHNs (![](http://latex2png.com/output//latex_53ee4d42efd7350fd65b18a35896b724.png)) have U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) charge ![](http://latex2png.com/output//latex_2dc15d2c5a0e12cfba957e961d3e1409.png) while one RHN (![](http://latex2png.com/output//latex_dd995354818d4ee415f15563032acf04.png)) has a ![](http://latex2png.com/output//latex_caf1daec479df34ced56808fc3620cec.png) charge. With a minimal extension of the Higgs sector, the three RHNs acquire their Majorana masses associated with U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) symmetry breaking. While ![](http://latex2png.com/output//latex_53ee4d42efd7350fd65b18a35896b724.png) have Yukawa coupling with the SM lepton doublets and play an essential role for the 'minimal seesaw' mechanism, ![](http://latex2png.com/output//latex_dd995354818d4ee415f15563032acf04.png) is isolated from the SM particles due to its U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) charge and hence it is a natural candidate for the dark matter (DM) without invoking additional symmetries. In this model context, we investigate the ![](http://latex2png.com/output//latex_351ece7db9fa4c7051a1487afddf5215.png)-portal RHN DM scenario, where the RHN DM communicates with the SM particles through the U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) gauge boson (![](http://latex2png.com/output//latex_351ece7db9fa4c7051a1487afddf5215.png) boson). We identify a narrow parameter space by combining the constraints from the observed DM relic abundance, the results of the search for a ![](http://latex2png.com/output//latex_351ece7db9fa4c7051a1487afddf5215.png) boson resonance at the Large Hadron Collider Run-2, and the gauge coupling perturbativity up to the Planck/Grand Unification scale. For a special choice of U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) charges for the SM fields allows us to extend the model to SU(5)![](http://latex2png.com/output//latex_9bb371b028aa239acb1b8bb6ea62dcaf.png)U(1)![](http://latex2png.com/output//latex_15313217a41b69fecc8ddfc8c358de63.png) grand unification. In this scenario, the model parameter space is more severely constrained, which will be explored at future high energy collider experiments.\n\n### [Neutrino physics with the PTOLEMY project: active neutrino properties  and the light sterile case](http://arxiv.org/abs/1902.05508v2) (1902.05508v2)\n<i>PTOLEMY collaboration, M. G. Betti, M. Biasotti, A. Boscá, F. Calle, G. Cavoto, C. Chang, A. G. Cocco, A. P. Colijn, J. Conrad, N. D'Ambrosio, N. De Groot, P. F. de Salas, M. Faverzani, A. Ferella, E. Ferri, P. Garcia-Abia, I. García-Cortés, G. Garcia Gomez-Tejedor, S. Gariazzo, F. Gatti, C. Gentile, A. Giachero, J. E. Gudmundsson, Y. Hochberg, Y. Kahn, A. Kievsky, M. Lisanti, C. Mancini-Terracciano, G. Mangano, L. E. Marcucci, C. Mariani, J. Martínez, M. Messina, A. Molinero-Vela, E. Monticone, A. Moroño, A. Nucciotti, F. Pandolfi, S. Parlati, S. Pastor, J. Pedrós, C. Pérez de los Heros, O. Pisanti, A. D. Polosa, A. Puiu, I. Rago, Y. Raitses, M. Rajteri, N. Rossi, I. Rucandio, R. Santorelli, K. Schaeffner, C. G. Tully, M. Viviani, F. Zhao, K. M. Zurek</b>\n\n<h10>2019-02-14</h10>\n> The PTOLEMY project aims to develop a scalable design for a Cosmic Neutrino Background (CNB) detector, the first of its kind and the only one conceived that can look directly at the image of the Universe encoded in neutrino background produced in the first second after the Big Bang. The scope of the work for the next three years is to complete the conceptual design of this detector and to validate with direct measurements that the non-neutrino backgrounds are below the expected cosmological signal. In this paper we discuss in details the theoretical aspects of the experiment and its physics goals. In particular, we mainly address three issues. First we discuss the sensitivity of PTOLEMY to the standard neutrino mass scale. We then study the perspectives of the experiment to detect the CNB via neutrino capture on tritium as a function of the neutrino mass scale and the energy resolution of the apparatus. Finally, we consider an extra sterile neutrino with mass in the eV range, coupled to the active states via oscillations, which has been advocated in view of neutrino oscillation anomalies. This extra state would contribute to the tritium decay spectrum, and its properties, mass and mixing angle, could be studied by analyzing the features in the beta decay electron spectrum.\n\n### [Statistical separation of weak gravitational lensing and intrinsic  ellipticities based on galaxy colour information](http://arxiv.org/abs/1805.01240v2) (1805.01240v2)\n<i>Tim M. Tugendhat, Robert Reischke, Bjoern Malte Schaefer</b>\n\n<h10>2018-05-03</h10>\n> Intrinsic alignments of galaxies are recognised as one of the most important systematic in weak lensing surveys on small angular scales. In this paper we investigate ellipticity correlation functions that are measured separately on elliptical and spiral galaxies, for which we assume the generic alignment mechanisms based on tidal shearing and tidal torquing, respectively. Including morphological information allows to find linear combinations of measured ellipticity correlation functions which suppress the gravitational lensing signal completely or which show a strongly boosted gravitational lensing signal relative to intrinsic alignments. Specifically, we find that ![](http://latex2png.com/output//latex_32d62ce47a9bc66ac7be2d98007fe25c.png) intrinsic alignment spectra can be measured in a model-independent way at a significance of ![](http://latex2png.com/output//latex_314a9a14b4bca98574719015dbe29be8.png) with a wide-angle tomographic survey such as Euclid's, ![](http://latex2png.com/output//latex_b9c120a0bfe04fdd27929ab748b184d1.png) intrinsic alignment model parameters can be determined at percent-level precision, ![](http://latex2png.com/output//latex_cc3c86f1f2cc917b9e59aff305853dd7.png) this measurement is not impeded by misclassifying galaxies and assuming a wrong alignment model, ![](http://latex2png.com/output//latex_a73f67128ed0778ace1f130d8df2cf67.png) parameter estimation from a cleaned weak lensing spectrum is possible with almost no bias and ![](http://latex2png.com/output//latex_82b1c2e8c4ba290640cf27ae8e3ab8a0.png) the misclassification would not strongly impact parameter estimation from the boosted weak lensing spectrum.\n\n### [Quantifying dimensionality: Bayesian cosmological model complexities](http://arxiv.org/abs/1903.06682v2) (1903.06682v2)\n<i>Will Handley, Pablo Lemos</b>\n\n<h10>2019-03-15</h10>\n> We demonstrate a measure for the effective number of parameters constrained by a posterior distribution in the context of cosmology. In the same way that the mean of the Shannon information (i.e. the Kullback-Leibler divergence) provides a measure of the strength of constraint between prior and posterior, we show that the variance of the Shannon information gives a measure of dimensionality of constraint. We examine this quantity in a cosmological context, applying it to likelihoods derived from Cosmic Microwave Background, large scale structure and supernovae data. We show that this measure of Bayesian model dimensionality compares favourably both analytically and numerically in a cosmological context with the existing measure of model complexity used in the literature.\n\n### [Analyzing billion-objects catalog interactively: Apache Spark for  physicists](http://arxiv.org/abs/1807.03078v2) (1807.03078v2)\n<i>S. Plaszczynski, J. Peloton, C. Arnault, J. E. Campagne</b>\n\n<h10>2018-07-09</h10>\n> Apache Spark is a Big Data framework for working on large distributed datasets. Although widely used in the industry, it remains rather limited in the academic community or often restricted to software engineers. The goal of this paper is to show with practical uses-cases that the technology is mature enough to be used without excessive programming skills by astronomers or cosmologists in order to perform standard analyses over large datasets, as those originating from future galaxy surveys. To demonstrate it, we start from a realistic simulation corresponding to 10 years of LSST data taking (6 billions of galaxies). Then, we design, optimize and benchmark a set of Spark python algorithms in order to perform standard operations as adding photometric redshift errors, measuring the selection function or computing power spectra over tomographic bins. Most of the commands execute on the full 110 GB dataset within tens of seconds and can therefore be performed interactively in order to design full-scale cosmological analyses. A jupyter notebook summarizing the analysis is available at https://github.com/astrolabsoftware/1807.03078.\n\n# <center>High Energy Astrophysical Phenomena</center> \n <hr> \n\n### [Multiwavelength characterisation of the accreting millisecond X-ray  pulsar and ultra-compact binary IGR J17062-6143](http://arxiv.org/abs/1801.03006v2) (1801.03006v2)\n<i>J. V. Hernandez Santisteban, V. Cuneo, N. Degenaar, J. van den Eijnden, D. Altamirano, M. N. Gomez, D. M. Russell, R. Wijnands, R. Golovakova, M. T. Reynolds, J. M. Miller</b>\n\n<h10>2018-01-09</h10>\n> IGR J17062-6143 is an ultra-compact X-ray binary (UCXB) with an orbital period of 37.96 min. It harbours a millisecond X-ray pulsar that is spinning at 163 Hz and and has continuously been accreting from its companion star since 2006. Determining the composition of the accreted matter in UCXBs is of high interest for studies of binary evolution and thermonuclear burning on the surface of neutron stars. Here, we present a multi-wavelength study of IGR J17062-6143 aimed to determine the detailed properties of its accretion disc and companion star. The multi-epoch photometric UV to near-infrared spectral energy distribution (SED) is consistent with an accretion disc ![](http://latex2png.com/output//latex_3bd8ab4ee2e57fe36f7c0cd7e424980e.png). The SED modelling of the accretion disc allowed us to estimate an outer disc radius of ![](http://latex2png.com/output//latex_d9f3155227c0c3698171184bdcb6e5fb.png) cm and a mass-transfer rate of ![](http://latex2png.com/output//latex_c7dedbfcd02e4e5ed3981b500c26e0d9.png) M![](http://latex2png.com/output//latex_dcec02f6cce6e40c0277b666220fbb50.png) yr![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png). Comparing this with the estimated mass-accretion rate inferred from its X-ray emission suggests that ![](http://latex2png.com/output//latex_9de9465816f4602a97db97c37c802b91.png)90% of the transferred mass is lost from the system. Moreover, our SED modelling shows that the thermal emission component seen in the X-ray spectrum is highly unlikely from the accretion disc and must therefore represent emission from the surface of the neutron star. Our low-resolution optical spectrum revealed a blue continuum and no emission lines, i.e. lacking H and He features. Based on the current data we cannot conclusively identify the nature of the companion star, but we make recommendations for future study that can distinguish between the different possible evolution histories of this X-ray binary. Finally, we demonstrate how multiwavelength observations can be effectively used to find more UCXBs among the LMXBs.\n\n### [3D MHD simulations and synthetic radio emission from an oblique rotating  magnetic massive star](http://arxiv.org/abs/1907.07068v1) (1907.07068v1)\n<i>Simon Daley-Yates, Ian R. Stevens, Asif ud-Doula</b>\n\n<h10>2019-07-16</h10>\n> We have performed 3D isothermal MHD simulation of a magnetic rotating massive star with a non-zero dipole obliquity and predicted the radio/sub-mm observable lightcurves and continuum spectra for a frequency range compatible with ALMA. From these results we also compare the model input mass-loss to that calculated from the synthetic thermal emission. Spherical and cylindrical symmetry is broken due to the obliquity of the stellar magnetic dipole resulting in an inclination and phase dependence of both the spectral flux and inferred mass-loss rate, providing testable predictions of variability for oblique rotator. Both quantities vary by factors between 2 and 3 over a full rotational period of the star, demonstrating that the role of rotation as critical in understanding the emission. This illustrates the divergence from a symmetric wind, resulting in a two armed spiral structure indicative of a oblique magnetic rotator. We show that a constant spectral index, ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png), model agrees well with our numerical prediction for a spherical wind for ![](http://latex2png.com/output//latex_92ace74d6703028689d8ff93f02c313a.png), however it is unable to capture the behavior of emission at ![](http://latex2png.com/output//latex_c2dd60a7bbce49d3beb1ec7943d30f60.png). As such we caution the use of such constant ![](http://latex2png.com/output//latex_879bee8d9bc4848dee78650baeff05fd.png) models for predicting emission from non-spherical winds such as those which form around magnetic massive stars.\n\n### [The nature of the soft-excess and spectral variability in the Seyfert 1  galaxy Zw 229.015](http://arxiv.org/abs/1907.07048v1) (1907.07048v1)\n<i>S. Tripathi, S. G. H. Waddell, L. C. Gallo, W. F. Welsh, C-Y. Chiang</b>\n\n<h10>2019-07-16</h10>\n> We have carried out a systematic analysis of the nearby (z=0.0279) active galaxy Zw 229.015 using multi-epoch, multi-instrument and deep pointed observations with XMM-Newton, Suzaku, Swift and NuSTAR. Spectral and temporal variability are examined in detail on both the long (weeks-to-years) and short (hours) timescales. A deep Suzaku observation of the source shows two distinct spectral states; a bright-soft state and a dim-hard state in which changes in the power law component account for the differences. Partial covering, blurred reflection and soft Comptonisation models describe the X-ray spectra comparably well, but the smooth, rather featureless, spectrum may be favouring the soft Comptonisation scenario. Moreover, independent of the spectral model, the observed spectral variability is ascribed to the changes in the power law continuum only and do not require changes in the properties of the absorber or blurred reflector incorporated in the other scenarios. The multi-epoch observations between 2009 and 2018 can be described in similar fashion. This could be understood if the primary emission is originating at a large distance from a standard accretion disc or if the disc is optically thin and geometrically thick as recently proposed for Zw 229.015. Our investigation shows that Zw 229.015 behaves similar to sources like Akn 120 and Mrk 530, that exhibit a strong soft-excess, but weak Compton hump and Fe K![](http://latex2png.com/output//latex_966896c8577c51b07260186d88ec1004.png) emission.\n\n### [The r-process nucleosynthesis in the outflows from short GRB accretion  disks](http://arxiv.org/abs/1907.00809v2) (1907.00809v2)\n<i>Agnieszka Janiuk</b>\n\n<h10>2019-07-01</h10>\n> Short gamma-ray bursts require a rotating black hole, surrounded by a magnetized relativistic accretion disk, such as the one formed by coalescing binary neutron stars or neutron star - black hole systems. The accretion onto a Kerr black hole is the mechanism of launching a baryon-free relativistic jet. An additional uncollimated outflow, consisting of sub-relativistic neutron-rich material which becomes unbound by thermal, magnetic and viscous forces, is responsible for blue and red kilonova. We explore the formation, composition and geometry of the secondary outflow by means of simulating accretion disks with relativistic magneto-hydrodynamics and employing realistic nuclear equation of state. We calculate the nucleosynthetic r-process yields by sampling the outflow with a dense set of tracer particles. Nuclear heating from the residual r-process radioactivities in the freshly synthesized nuclei is expected to power a red kilonova, contributing independently from the dynamical ejecta component, launched at the time of merger, and neutron-poor broad polar outflow, launched from the surface of the hypermassive neutron star by neutrino wind. Our simulations show that both magnetisation of the disk and high black hole spin are able to launch fast wind outflows (![](http://latex2png.com/output//latex_96a938600c0af528df36c673cd70791d.png)) with a broad range of electron fraction ![](http://latex2png.com/output//latex_e8aefca062cf9aa4e57055f9b81f8045.png), and help explain the multiple components observed in the kilonova lightcurves. The total mass loss from the post-merger disk via unbound outflows is between 2\\% and 17\\% of the initial disk mass.\n\n### [The Giant Radio Array for Neutrino Detection (GRAND): Science and Design](http://arxiv.org/abs/1810.09994v2) (1810.09994v2)\n<i>GRAND Collaboration, Jaime Alvarez-Muniz, Rafael Alves Batista, Aswathi Balagopal V., Julien Bolmont, Mauricio Bustamante, Washington R. Carvalho, Didier Charrier, Ismael Cognard, Valentin Decoene, Peter B. Denton, Sijbrand J. De Jong, Krijn D. De Vries, Ralph Engel, Ke Fang, Chad Finley, Stefano Gabici, QuanBu Gou, Junhua Gu, Claire Guépin, Hongbo Hu, Yan Huang, Kumiko Kotera, Sandra Le Coz, Jean-Philippe Lenain, Guo-Liang Lu, Olivier Martineau-Huynh, Miguel Mostafá, Fabrice Mottez, Kohta Murase, Valentin Niess, Foteini Oikonomou, Tanguy Pierog, Xiangli Qian, Bo Qin, Duan Ran, Nicolas Renault-Tinacci, Markus Roth, Frank G. Schröder, Fabian Schüssler, Cyril Tasse, Charles Timmermans, Matias Tueros, Xiangping Wu, Philippe Zarka, Andreas Zech, B. Theodore Zhang, Jianli Zhang, Yi Zhang, Qian Zheng, Anne Zilles</b>\n\n<h10>2018-10-23</h10>\n> The Giant Radio Array for Neutrino Detection (GRAND) is a planned large-scale observatory of ultra-high-energy (UHE) cosmic particles, with energies exceeding 10^8 GeV. Its goal is to solve the long-standing mystery of the origin of UHE cosmic rays. To do this, GRAND will detect an unprecedented number of UHE cosmic rays and search for the undiscovered UHE neutrinos and gamma rays associated to them with unmatched sensitivity. GRAND will use large arrays of antennas to detect the radio emission coming from extensive air showers initiated by UHE particles in the atmosphere. Its design is modular: 20 separate, independent sub-arrays, each of 10 000 radio antennas deployed over 10 000 km^2. A staged construction plan will validate key detection techniques while achieving important science goals early. Here we present the science goals, detection strategy, preliminary design, performance goals, and construction plans for GRAND.\n\n# <center>Instrumentation And Methods In Astrophysics</center> \n <hr> \n\n### [Primarily Undergraduate Institutions and the Astronomy Community](http://arxiv.org/abs/1907.07118v1) (1907.07118v1)\n<i>Joseph Ribaudo, Rebecca A. Koopmann, Aileen A. O'Donoghue, Aparna Venkatesan</b>\n\n<h10>2019-07-16</h10>\n> This White Paper highlights the role Primarily Undergraduate Institutions (PUIs) play within the astronomy profession, addressing issues related to employment, resources and support, research opportunities and productivity, and educational and societal impacts, among others. Astronomers working at PUIs are passionate about teaching and mentoring undergraduate students through substantive astronomy experiences, all while working to continue research programs that contribute to the advancement of the professional field of astronomy. PUIs are where the majority of undergraduate students pursue post-secondary education, and as such, understanding the unique challenges and opportunities associated with PUIs is critical to fostering an inclusive astronomy community throughout the next decade. We provide a view of the profession as lived and experienced by faculty and students of PUIs, while highlighting the unique opportunities, challenges, and obstacles routinely faced. A variety of recommendations are outlined to provide the supporting structures and resources needed for astronomy to thrive at PUIs over the next decade and beyond - a critical step for a profession focused on fostering and maintaining an inclusive, supportive, and diverse community.\n\n### [Coronagraphic phase diversity through residual turbulence: performance  study and experimental validation](http://arxiv.org/abs/1907.07038v1) (1907.07038v1)\n<i>Olivier Herscovici-Schiller, Jean-François Sauvage, Laurent M. Mugnier, Kjetil Dohlen, Arthur Vigan</b>\n\n<h10>2019-07-16</h10>\n> Quasi-static aberrations in coronagraphic systems are the ultimate limitation to the capabilities of exoplanet imagers both ground-based and space-based. These aberrations - which can be due to various causes such as optics alignment or moving optical parts during the observing sequence - create light residuals called speckles in the focal plane that might be mistaken for a planets. For ground-based instruments, the presence of residual turbulent wavefront errors due to partial adaptive optics correction causes an additional difficulty to the challenge of measuring aberrations in the presence of a coronagraph. In this paper, we present an extension of COFFEE, the coronagraphic phase diversity, to the estimation of quasi-static aberrations in the presence of adaptive optics-corrected residual turbulence. We perform realistic numerical simulations to assess the performance that can be expected on an instrument of the current generation. We perform the first experimental validation in the laboratory which demonstrates that quasistatic aberrations can be corrected during the observations by means of coronagraphic phase diversity.\n\n### [Ex Luna, Scientia: The Lunar Occultation eXplorer (LOX)](http://arxiv.org/abs/1907.07005v1) (1907.07005v1)\n<i>R. S. Miller, M. Ajello, J. F. Beacom, P. F. Bloser, A. Burrows, C. L. Fryer, J. O. Goldsten, D. H. Hartmann, P. Hoeflich, A. Hungerford, D. J. Lawrence, M. D. Leising, P. Milne, P. N. Peplowski, F. Shiraz, T. Sukhbold, L. -S. The, Z. Yokley, C. A. Young</b>\n\n<h10>2019-07-16</h10>\n> LOX is a lunar-orbiting astrophysics mission that will probe the cosmos at MeV energies. It is guided by open questions regarding thermonuclear, or Type-Ia, supernovae (SNeIa) and will characterize these inherently radioactive objects by enabling a systematic survey of SNeIa at gamma-ray energies for the first time. Astronomical investigations from lunar orbit afford new opportunities to advance our understanding of the cosmos. The foundation of LOX is an observational approach well suited to the all-sky monitoring demands of supernova investigations and time-domain astronomy. Its inherently wide field-of-view and continuous all-sky monitoring provides an innovative way of addressing decadal survey questions at MeV energies (0.1-10 MeV). The LOX approach achieves high sensitivity with a simple, high-heritage instrument design that eliminates the need for complex, position-sensitive detectors, kinematic event reconstruction, masks, or other insensitive detector mass, while also mitigating technology development, implementation complexity, and their associated costs. LOX can be realized within existing programs, like Explorer.\n\n### [Occultation observations of Saturn's rings with Cassini VIMS](http://arxiv.org/abs/1907.06980v1) (1907.06980v1)\n<i>P. D. Nicholson, T. Ansty, M. M. Hedman, D. Creel, J. Ahlers, R. A. Harbison, R. H. Brown, R. N. Clark, K. H. Baines, B. J. Buratti, C. Sotin, S. V. Badman</b>\n\n<h10>2019-07-16</h10>\n> We describe the prediction, design, execution and calibration of stellar and solar occultation observations of Saturn's rings by the Visual and Infrared Mapping Spectrometer (VIMS) instrument on the Cassini spacecraft. Particular attention is paid to the technique developed for onboard acquisition of the stellar target and to the geometric and photometric calibration of the data. Examples of both stellar and solar occultation data are presented, highlighting several aspects of the data as well as the different occultation geometries encountered during Cassini's 13 year orbital tour. Complete catalogs of ring stellar and solar occultations observed by Cassini-VIMS are presented, as a guide to the standard data sets which have been delivered to the Planetary Data System's Ring Moon Systems Node.\n\n### [Astro2020 APC White Paper: Durable Agency Support for Exoplanet Catalogs  and Archives](http://arxiv.org/abs/1907.06977v1) (1907.06977v1)\n<i>Joshua Pepper, David Ciardi, Todd Henry, Susan Mullally</b>\n\n<h10>2019-07-16</h10>\n> Many projects in current exoplanet science make use of catalogs of known exoplanets and their host stars. These may be used for demographic, population, and statistical studies, or for identifying targets for future observations. The ability to efficiently and accurately conduct exoplanet science depends on the completeness, accuracy, and access to these catalogs. In this white paper, we argue that long-term agency support and maintenance of exoplanet archives is of crucial importance to achieving the scientific goals of the community and the strategic goals of the funding agencies. As such, it is imperative that these facilities are appropriately supported and maintained by the national funding agencies.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics A |2019-07-17",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Astrophysics Of Galaxies</center> \n <hr> \n\n### [Spiral instabilities: Mechanism for recurrence](http://arxiv.org/abs/1906.04191v2) (1906.04191v2)\n<i>J. A. Sellwood, Ray G. Carlberg</b>\n\n<h10>2019-06-10</h10>\n> We argue that self-excited instabilities are the cause of spiral patterns in simulations of unperturbed stellar discs. In previous papers, we have found that spiral patterns were caused by a few concurrent waves, which we claimed were modes. The superposition of a few steadily rotating waves inevitably causes the appearance of the disc to change continuously, and creates the kind of shearing spiral patterns that have been widely reported. Although we have found that individual modes last for relatively few rotations, spiral activity persists because fresh instabilities appear, which we suspected were excited by the changes to the disc caused by previous disturbances. Here we confirm our suspicion by demonstrating that scattering at either of the Lindblad resonances seeds a new groove-type instability. With this logical gap closed, our understanding of the behaviour in the simulations is almost complete. We believe that our robust mechanism is a major cause of spiral patterns in the old stellar discs of galaxies, including the Milky Way where we have previously reported evidence for resonance scattering in the recently released Gaia data.\n\n### [Tidal disruption events from massive black hole binaries: predictions  for ongoing and future surveys](http://arxiv.org/abs/1811.01960v2) (1811.01960v2)\n<i>Stephen Thorp, Eli Chadwick, Alberto Sesana</b>\n\n<h10>2018-11-05</h10>\n> We compute the expected cosmic rates of tidal disruption events induced by individual massive black holes (MBHs) and by MBH binaries (MBHBs) - with a specific focus on the latter class - to explore the potential of TDEs to probe the cosmic population of sub-pc MBHBs. Rates are computed by combining MBH and MBHB population models derived from large cosmological simulations with estimates of the induced TDE rates for each class of objects. We construct empirical TDE spectra that fit a large number of observations in the optical, UV and X-ray and consider their observability by current and future survey instruments. Consistent with results in the literature, and depending on the detailed assumption of the model, we find that LSST and Gaia in optical and eROSITA in X-ray will observe a total of 3000-6000, 80-180 and 600-900 TDEs per year, respectively. Depending on the survey, one to several percent of these are prompted by MBHBs. In particular both LSST and eROSITA are expected to see 150-450 MBHB induced TDEs in their respective mission lifetimes, including 5-100 repeated flares. The latter provide an observational sample of binary candidates with relatively low contamination and have the potential of unveiling the sub-pc population of MBHBs in the mass range ![](http://latex2png.com/output//latex_1e2362cb53b3f36410f3db907ddfec75.png), thus informing future low frequency gravitational wave observatories.\n\n### [CosmoDC2: A Synthetic Sky Catalog for Dark Energy Science with LSST](http://arxiv.org/abs/1907.06530v1) (1907.06530v1)\n<i>Danila Korytov, Andrew Hearin, Eve Kovacs, Patricia Larsen, Esteban Rangel, Joseph Hollowed, Andrew J. Benson, Katrin Heitmann, Yao-Yuan Mao, Anita Bahmanyar, Chihway Chang, Duncan Campbell, Joseph Derose, Hal Finkel, Nicholas Frontiere, Eric Gawiser, Salman Habib, Benjamin Joachimi, François Lanusse, Nan Li, Rachel Mandelbaum, Christopher Morrison, Jeffrey A. Newman, Adrian Pope, Eli Rykoff, Melanie Simet, Chun-Hao To, Vinu Vikraman, Risa H. Wechsler, Martin White</b>\n\n<h10>2019-07-15</h10>\n> This paper introduces cosmoDC2, a large synthetic galaxy catalog designed to support precision dark energy science with the Large Synoptic Survey Telescope (LSST). CosmoDC2 is the starting point for the second data challenge (DC2) carried out by the LSST Dark Energy Science Collaboration (LSST DESC). The catalog is based on a trillion-particle, 4.225 Gpc^3 box cosmological N-body simulation, the `Outer Rim' run. It covers 440 deg^2 of sky area to a redshift of z=3 and is complete to a magnitude depth of 28 in the r-band. Each galaxy is characterized by a multitude of properties including stellar mass, morphology, spectral energy distributions, broadband filter magnitudes, host halo information and weak lensing shear. The size and complexity of cosmoDC2 requires an efficient catalog generation methodology; our approach is based on a new hybrid technique that combines data-driven empirical approaches with semi-analytic galaxy modeling. A wide range of observation-based validation tests has been implemented to ensure that cosmoDC2 enables the science goals of the planned LSST DESC DC2 analyses. This paper also represents the official release of the cosmoDC2 data set, including an efficient reader that facilitates interaction with the data.\n\n### [Are most Cataclysmic Variables in Globular Clusters dynamically formed?](http://arxiv.org/abs/1907.06527v1) (1907.06527v1)\n<i>Diogo Belloni, Mirek Giersz, Liliana E. Rivera Sandoval, Abbas Askar, Pawel Ciecielag</b>\n\n<h10>2019-07-15</h10>\n> We have been investigating populations of cataclysmic variables (CVs) in a set of more than 300 globular cluster (GC) models evolved with the MOCCA code. One of the main questions we have intended to answer is whether most CVs in GCs are dynamically formed or not. Contrary to what has been argued for a long time, we found that dynamical destruction of primordial CV progenitors is much stronger in GCs than dynamical formation of CVs. In particular, we found that, on average, the detectable CV population is predominantly composed of CVs formed via a typical common envelope phase (> 70 per cent). However, core-collapsed models tend to have higher fractions of bright CVs than non-core-collapsed ones, which suggests then that the formation of CVs is indeed slightly favoured through strong dynamical interactions in core-collapsed GCs, due to the high stellar densities in their cores.\n\n### [A comprehensive and uniform sample of broad-line active galactic nuclei  from the SDSS DR7](http://arxiv.org/abs/1906.05597v2) (1906.05597v2)\n<i>He-Yang Liu, Wen-Juan Liu, Xiao-Bo Dong, Hongyan Zhou, Tinggui Wang, Honglin Lu, Weimin Yuan</b>\n\n<h10>2019-06-13</h10>\n> A new, complete sample of 14,584 broad-line AGNs at ![](http://latex2png.com/output//latex_edf02a87f720d6f84d6e9839045df10d.png) is presented, which are uncovered homogeneously from the complete database of galaxies and quasars observed spectroscopically in the Sloan Digital Sky Survey Seventh Data Release. The stellar continuum is properly removed for each spectrum with significant host absorption line features, and careful analyses of the emission-line spectra, particularly in the H![](http://latex2png.com/output//latex_677f947c0735cc50346e1da58b0cda67.png) and H![](http://latex2png.com/output//latex_8aff8134228111dd32b938d4401dbd8c.png) wavebands, are carried out. The broad Balmer emission line, particularly, H![](http://latex2png.com/output//latex_677f947c0735cc50346e1da58b0cda67.png), is used to indicate the presence of an AGN. The broad H![](http://latex2png.com/output//latex_677f947c0735cc50346e1da58b0cda67.png) lines have luminosities in a range of ![](http://latex2png.com/output//latex_74744268c68ee5f43da98febcc6ae775.png)-![](http://latex2png.com/output//latex_71afb1e7b3c54fe4ecf648bd26d46dae.png) erg s![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png), and line widths (FWHMs) of 500-34,000 km s![](http://latex2png.com/output//latex_e88d606bccc35225e828408fb7c65db9.png). The virial black hole masses, estimated from the broad line measurements, span a range of ![](http://latex2png.com/output//latex_3a2b17bf8ee727099ff0648d547a3d59.png)-![](http://latex2png.com/output//latex_b242c9cbeb7790329b1311c67fdabc07.png) ![](http://latex2png.com/output//latex_1594f459578e6116dc520c94993eb2a7.png), and the Eddington ratios vary from ![](http://latex2png.com/output//latex_af89889240fa0a53b4c9abcd35cdebd2.png) to ![](http://latex2png.com/output//latex_95b99e2f4e8c962311549d18e3f12dbc.png) in logarithmic scale. Other quantities such as multi-wavelength photometric properties and flags denoting peculiar line profiles are also included in this catalog. We describe the construction of this catalog and briefly discuss its properties. The catalog is publicly available online. This homogeneously selected AGN catalog, along with the accurately measured spectral parameters, provide the most updated, largest AGN sample data, which will enable further comprehensive investigations of the properties of the AGN population in the low-redshift universe.\n\n# <center>Earth And Planetary Astrophysics</center> \n <hr> \n\n### [Kepler Object of Interest Network III. Kepler-82f: A new non-transiting  ![](http://latex2png.com/output//latex_8d417d1b9caf07670a14adf331692c60.png) planet from photodynamical modelling](http://arxiv.org/abs/1907.06534v1) (1907.06534v1)\n<i>J. Freudenthal, C. von Essen, A. Ofir, S. ~Dreizler, E. Agol, S. Wedemeyer, B. M. Morris, A. C. Becker, H. J. Deeg, S. Hoyer, M. Mallonn, K. Poppenhaeger, E. Herrero, I. Ribas, P. Boumis, A. Liakos</b>\n\n<h10>2019-07-15</h10>\n> Context. The Kepler Object of Interest Network (KOINet) is a multi-site network of telescopes around the globe organised for follow-up observations of transiting planet candidate Kepler objects of interest (KOIs) with large transit timing variations (TTVs). The main goal of KOINet is the completion of their TTV curves as the Kepler telescope stopped observing the original Kepler field in 2013.   Aims. We ensure a comprehensive characterisation of the investigated systems by analysing Kepler data combined with new ground-based transit data using a photodynamical model. This method is applied to the Kepler-82 system leading to its first dynamic analysis.   Methods. In order to provide a coherent description of all observations simultaneously, we combine the numerical integration of the gravitational dynamics of a system over the time span of observations with a transit light curve model. To explore the model parameter space, this photodynamical model is coupled with a Markov chain Monte Carlo algorithm.   Results. The Kepler-82b/c system shows sinusoidal TTVs due to their near 2:1 resonance dynamical interaction. An additional chopping effect in the TTVs of Kepler-82c hints to a further planet near the 3:2 or 3:1 resonance. We photodynamically analysed Kepler long- and short-cadence data and three new transit observations obtained by KOINet between 2014 and 2018. Our result reveals a non-transiting outer planet with a mass of ![](http://latex2png.com/output//latex_8bf632e03ed83fe919a799d44eec2739.png) near the 3:2 resonance to the outermost known planet, Kepler-82c. Furthermore, we determined the densities of planets b and c to the significantly more precise values ![](http://latex2png.com/output//latex_6ae5e6dcdc86cee10fd7cb2cd0312b04.png) and ![](http://latex2png.com/output//latex_a5c64c015564e4cb92d4a8940ca1a10a.png).\n\n### [Virtual European Solar & Planetary Access (VESPA): a Planetary Science  Virtual Observatory cornerstone](http://arxiv.org/abs/1907.06521v1) (1907.06521v1)\n<i>S. Erard, B. Cecconi, P. Le Sidaner, C. Chauvin, A. P. Rossi, M. Minin, T. Capria, S. Ivanovski, B. Schmitt, V. Genot, N. Andre, C. Marmo, A. C. Vandaele, L. Trompet, M. Scherf, R. Hueso, A. Maattanen, B. Carry, N. Achilleos, J. Soucek, D. Pisa, K. Benson, P. Fernique, E. Millour</b>\n\n<h10>2019-07-15</h10>\n> The Europlanet-2020 programme, started Sept 1st, 2015 for 4 years, includes an activity called VESPA which focuses on adapting Virtual Observatory (VO) techniques to handle Planetary Science data. The main objectives of VESPA are to facilitate searches both in big archives and in small databases, to enable data analysis by providing simple data access and on-line visualization functions, and to allow research teams to publish derived data in an interoperable environment as easily as possible. VESPA encompasses a wide scope, including surfaces, atmospheres, magnetospheres and planetary plasmas, small bodies, heliophysics, exoplanets, and spectroscopy in solid phase. This system relies in particular on standards and tools developed for the Astronomy VO (IVOA) and extends them where required to handle specificities of Solar System studies. It also aims at making the VO compatible with tools and protocols developed in different contexts, for instance GIS for planetary surfaces, or time series tools for plasma-related measurements. An essential part of the activity is to publish a significant amount of high-quality data in this system, with a focus on derived products resulting from data analysis or simulations.\n\n### [Zinc isotope analyses of singularly small samples (<5 ng Zn):  investigating chondrule-matrix complementarity in Leoville](http://arxiv.org/abs/1907.06501v1) (1907.06501v1)\n<i>Elishevah van Kooten, Frederic Moynier</b>\n\n<h10>2019-07-15</h10>\n> The potential complementarity between chondrules and matrix of chondrites, the Solar System's building blocks, is still a highly debated subject. Complementary superchrondritic compositions of chondrite matrices and subchondritic chondrules may point to formation of these components within the same reservoir or, alternatively, to mobilization of elements during secondary alteration on chondrite parent bodies. Zinc isotope fractionation through evaporation during chondrule formation may play an important role in identifying complementary relationships between chondrules and matrix and is additionally a mobile element during hydrothermal processes. In an effort to distinguish between primary Zn isotope fractionation during chondrule formation and secondary alteration, we here report the Zn isotope data of five chondrule cores, five corresponding igneous rims and two matrices of the relatively unaltered Leoville CV3.1 chondrite. The detail required for these analyses necessitated the development of an adjusted Zn isotope analyses protocol outlined in this study.\n\n### [Final spin states of eccentric ocean planets](http://arxiv.org/abs/1907.06451v1) (1907.06451v1)\n<i>Pierre Auclair-Desrotour, Jérémy Leconte, Emeline Bolmont, Stéphane Mathis</b>\n\n<h10>2019-07-15</h10>\n> Eccentricity tides generate a torque that can drive an ocean planet towards asynchronous rotation states of equilibrium when enhanced by resonances associated with the oceanic tidal modes. We investigate the impact of eccentricity tides on the rotation of rocky planets hosting a thin uniform ocean and orbiting cool dwarf stars such as TRAPPIST-1, with orbital periods ~1-10 days. Combining the linear theory of oceanic tides in the shallow water approximation with the Andrade model for the solid part of the planet, we develop a global model including the coupling effects of ocean loading, self-attraction, and deformation of the solid regions. We derive from this model analytic solutions for the tidal Love numbers and torque exerted on the planet. These solutions are used with realistic values of parameters provided by advanced models of the internal structure and tidal oscillations of solid bodies to explore the parameter space both analytically and numerically. Our model allows us to fully characterise the frequency-resonant tidal response of the planet, and particularly the features of resonances associated with the oceanic tidal modes (eigenfrequencies, resulting maxima of the tidal torque and Love numbers) as functions of the planet parameters (mass, radius, Andrade parameters, ocean depth and Rayleigh drag frequency). Resonances associated with the oceanic tide decrease the critical eccentricity beyond which asynchronous rotation states distinct from the usual spin-orbit resonances can exist. We provide an estimation and scaling laws for this critical eccentricity, which is found to be lowered by roughly one order of magnitude, switching from ~0.3 to ~0.06 in typical cases and to ~0.01 in extremal ones.\n\n### [A multi-wavelength study of the debris disc around 49 Cet](http://arxiv.org/abs/1907.06427v1) (1907.06427v1)\n<i>Nicole Pawellek, Attila Moór, Julien Milli, Ágnes Kóspál, Johan Olofsson, Péter Ábrahám, Miriam Keppler, Quentin Kral, Adriana Pohl, Jean-Charles Augereau, Anthony Boccaletti, Gaël Chauvin, Élodie Choquet, Natalia Engler, Thomas Henning, Maud Langlois, Eve J. Lee, François Ménard, Philippe Thébault, Alice Zurlo</b>\n\n<h10>2019-07-15</h10>\n> In a multi-wavelength study of thermal emission and scattered light images we analyse the dust properties and structure of the debris disc around the A1-type main sequence star 49~Cet. As a basis for this study, we present new scattered light images of the debris disc known to possess both a high amount of dust and gas. The outer region of the disc is revealed in former coronagraphic H-band and our new Y-band images from the Very Large Telescope SPHERE instrument. We use the knowledge of the disc's radial extent inferred from ALMA observations and the grain size distribution found by SED fitting to generate semi-dynamical dust models of the disc. We compare the models to scattered light and thermal emission data and find that a disc with a maximum of the surface density at 110~au and shallow edges can describe both thermal emission and scattered light observations. This suggests that grains close to the blow-out limit and large grains stem from the same planetesimal population and are mainly influenced by radiation pressure. The influence of inwards transport processes could not be analysed in this study.\n\n# <center>Solar And Stellar Astrophysics</center> \n <hr> \n\n### [The prevalence of repeating fast radio bursts](http://arxiv.org/abs/1907.06619v1) (1907.06619v1)\n<i>Vikram Ravi</b>\n\n<h10>2019-07-15</h10>\n> Fast radio bursts are extragalactic, sub-millisecond radio impulses of unknown origin [1,2]. Their dispersion measures, which quantify the observed frequency-dependent dispersive delays in terms of free-electron column densities, significantly exceed predictions from models [3] of the Milky Way interstellar medium. The excess dispersions are likely accrued as fast radio bursts propagate through their host galaxies, gaseous galactic halos and the intergalactic medium [4,5]. Despite extensive follow-up observations of the published sample of 72 burst sources [6], only two are observed to repeat [7,8], and it is unknown whether or not the remainder are truly one-off events. Here I show that the volumetric occurrence rate of so far non-repeating fast radio bursts likely exceeds the rates of candidate cataclysmic progenitor events, and also likely exceeds the birth rates of candidate compact-object sources. This analysis is based on the high detection rate of bursts with low dispersion measures by the Canadian Hydrogen Intensity Mapping Experiment [9]. Within the existing suite of astrophysical scenarios for fast radio burst progenitors, I conclude that most observed cases originate from sources that emit several bursts over their lifetimes.\n\n### [Predictions for solar flares activity in solar cycle 25](http://arxiv.org/abs/1907.06545v1) (1907.06545v1)\n<i>Eleni Petrakou</b>\n\n<h10>2019-07-15</h10>\n> A forecast for the evolution of solar cycle 25 in terms of solar flares activity is presented. The forecast is derived from an existing phenomenological model based on the coupling of an internal solar component and a planetary component. In addition to sufficient temporal resolution, the predictions are characterized by features which both differentiate the model from other methods for space climate prediction and make it falsifiable.\n\n### [Are most Cataclysmic Variables in Globular Clusters dynamically formed?](http://arxiv.org/abs/1907.06527v1) (1907.06527v1)\n<i>Diogo Belloni, Mirek Giersz, Liliana E. Rivera Sandoval, Abbas Askar, Pawel Ciecielag</b>\n\n<h10>2019-07-15</h10>\n> We have been investigating populations of cataclysmic variables (CVs) in a set of more than 300 globular cluster (GC) models evolved with the MOCCA code. One of the main questions we have intended to answer is whether most CVs in GCs are dynamically formed or not. Contrary to what has been argued for a long time, we found that dynamical destruction of primordial CV progenitors is much stronger in GCs than dynamical formation of CVs. In particular, we found that, on average, the detectable CV population is predominantly composed of CVs formed via a typical common envelope phase (> 70 per cent). However, core-collapsed models tend to have higher fractions of bright CVs than non-core-collapsed ones, which suggests then that the formation of CVs is indeed slightly favoured through strong dynamical interactions in core-collapsed GCs, due to the high stellar densities in their cores.\n\n### [Fuse and IUE Spectroscopy of the Prototype Dwarf Nova ER Ursa Majoris  During Quiescence](http://arxiv.org/abs/1907.06513v1) (1907.06513v1)\n<i>Giannina Guzman, Edward Sion, Patrick Godon</b>\n\n<h10>2019-07-15</h10>\n> ER Ursae Majoris is the prototype for a subset of SU UMa-type dwarf novae characterized by short cycle times between outburst, high outburst frequency, and ``negative'' superhumps. It suffers superoutbursts every 43 days, lasting 20 days, normal outbursts every 4 days and has an outburst amplitude of 3 magnitudes. We have carried out a far ultraviolet (FUV) spectral analysis of ER UMa in quiescence, by fitting Far Ultraviolet Spectroscopic Explorer (FUSE) and International Ultraviolet Explorer (IUE) spectra with model accretion disks and high gravity photosphere models. Using the Gaia parallax distance and an orbital inclination of ![](http://latex2png.com/output//latex_9d8455f9c4e0d2344d1a37098f2c9b8b.png), we find that during the brief quiescence of only four days, the accretion rate is ![](http://latex2png.com/output//latex_673bf60178b6c0131c65eda784af76df.png)/yr, with the ER UMa white dwarf contributing 55% of the FUV flux and the accretion disk contributing the remaining 45\\% of the flux. The white dwarf in ER UMa is markedly hotter (32,000~K) than the other white dwarfs in dwarf novae below the CV period gap which have typical temperatures ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)15,000~K. For a higher inclinations of 60 to 75 degrees, the accretion rates that we derive are roughly an order of magnitude higher ![](http://latex2png.com/output//latex_cfbb22626c948cfe7558dd30887536a4.png)/yr.\n\n### [StePar: an automatic code to infer stellar atmospheric parameters](http://arxiv.org/abs/1907.06512v1) (1907.06512v1)\n<i>H. M. Tabernero, E. Marfil, D. Montes, J. I. González Hernández</b>\n\n<h10>2019-07-15</h10>\n> Context: StePar is an automatic code written in Python 3.X designed to compute the stellar atmospheric parameters Teff, log(g), [Fe/H], and of FGK-type stars by means of the EW method. This code has already been extensively tested in different spectroscopic studies of FGK-type stars with several spectrographs and against myriads of Gaia-ESO Survey UVES U580 spectra of late-type, low-mass stars as one of its thirteen pipelines.   Aims: We describe the code and test it against a library of well characterised Gaia benchmark stars. We also release the code to the community and provide the link for download.   Methods: We carried out the required EW determination of Fe I and Fe II spectral lines using the automatic tool TAME. StePar implements a grid of MARCS model atmospheres and the MOOG radiative transfer code to compute stellar atmospheric parameters by means of a Downhill Simplex minimisation algorithm.   Results: We show the results of the benchmark star test and also discuss the limitations of the EW method, and hence the code. In addition, we found a small internal scatter for the benchmark stars of 9 +- 32 K in Teff, 0.00 +- 0.07 dex in log(g), and 0.00 +- 0.03 dex in [Fe/H]. Finally, we advise against using StePar on double-lined spectroscopic binaries or spectra with R < 30,000, SNR < 20 or vsini >15 km/s as well as stars later than K4 or earlier than F6.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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      "title": "Latest Arxiv Papers In Astrophysics B |2019-07-16",
      "body": "<center><b>The Latest Research Papers in Astrophysics</b></center>\n\n# <center>Cosmology And Nongalactic Astrophysics</center> \n <hr> \n\n### [The prevalence of repeating fast radio bursts](http://arxiv.org/abs/1907.06619v1) (1907.06619v1)\n<i>Vikram Ravi</b>\n\n<h10>2019-07-15</h10>\n> Fast radio bursts are extragalactic, sub-millisecond radio impulses of unknown origin [1,2]. Their dispersion measures, which quantify the observed frequency-dependent dispersive delays in terms of free-electron column densities, significantly exceed predictions from models [3] of the Milky Way interstellar medium. The excess dispersions are likely accrued as fast radio bursts propagate through their host galaxies, gaseous galactic halos and the intergalactic medium [4,5]. Despite extensive follow-up observations of the published sample of 72 burst sources [6], only two are observed to repeat [7,8], and it is unknown whether or not the remainder are truly one-off events. Here I show that the volumetric occurrence rate of so far non-repeating fast radio bursts likely exceeds the rates of candidate cataclysmic progenitor events, and also likely exceeds the birth rates of candidate compact-object sources. This analysis is based on the high detection rate of bursts with low dispersion measures by the Canadian Hydrogen Intensity Mapping Experiment [9]. Within the existing suite of astrophysical scenarios for fast radio burst progenitors, I conclude that most observed cases originate from sources that emit several bursts over their lifetimes.\n\n### [Covariance matrices for galaxy cluster weak lensing: from virial regime  to uncorrelated large-scale structure](http://arxiv.org/abs/1907.06611v1) (1907.06611v1)\n<i>Hao-Yi Wu, David H. Weinberg, Andrés N. Salcedo, Benjamin D. Wibking, Ying Zu</b>\n\n<h10>2019-07-15</h10>\n> Next-generation optical imaging surveys will revolutionise the observations of weak gravitational lensing by galaxy clusters and provide stringent constraints on growth of structure and cosmic acceleration. In these experiments, accurate modelling of covariance matrices of cluster weak lensing plays the key role in obtaining robust measurements of the mean mass of clusters and cosmological parameters. We use a combination of analytical calculations and high-resolution N-body simulations to derive accurate covariance matrices that span from the virial regime to linear scales of the cluster-matter cross-correlation. We validate this calculation using a public ray-tracing lensing simulation and provide a software package for calculating covariance matrices for a wide range of cluster and source sample choices. We discuss the relative importance of shape noise and density fluctuations, the impact of radial bin size, and the impact of off-diagonal elements. For a weak lensing source density 10 per square arcmin, shape noise typically dominates the variance on comoving scales less than 5 Mpc/h. However, for 60 per square arcmin, potentially achievable with future weak lensing experiments, density fluctuations typically dominate the variance at scales greater than 1 Mpc/h and remain comparable to shape noise on smaller scales.\n\n### [Lens modelling of the strongly lensed Type Ia supernova iPTF16geu](http://arxiv.org/abs/1907.06609v1) (1907.06609v1)\n<i>E. Mörtsell, J. Johansson, S. Dhawan, A. Goobar, R. Amanullah, D. A. Goldstein</b>\n\n<h10>2019-07-15</h10>\n> Improved observational constraints on the strongly lensed Type Ia supernova iPTF16geu, including the time delay between images, are used to decrease uncertainties in the lens model by a factor ![](http://latex2png.com/output//latex_1c7eea3249d1b76f3a86da32c16494d0.png) and to investigate the dependence on the universal expansion rate ![](http://latex2png.com/output//latex_b43abea0236123d545a179ca0f33aafa.png). We constrain a combination of the dimensionless Hubble constant, ![](http://latex2png.com/output//latex_f57eff42fcc31770d06661289bfff310.png), and the slope of the projected surface density of the lens galaxy, ![](http://latex2png.com/output//latex_14e6118a05ec8754a2c612588adfd015.png), at ![](http://latex2png.com/output//latex_1fba79df1969f4fd8d2e673fbee19a20.png), to ![](http://latex2png.com/output//latex_9273eea1557b26569b95e5d46bbf8549.png). This implies ![](http://latex2png.com/output//latex_e77047cadd2c9a549e8d985c7e20476b.png) using our current knowledge of the expansion rate, corresponding to a flatter surface density than an isothermal halo for which ![](http://latex2png.com/output//latex_7de7fc663d5abad7f51c91a069c0c2f5.png). Regardless of the slope, a smooth lens density fails to explain the iPTF16geu image fluxes, and additional sub-structure lensing is needed. Taking advantage of the standard candle nature of the source and including stellar microlensing, we show that the probability to obtain the observed fluxes is maximized for ![](http://latex2png.com/output//latex_46e30ac8a3cc4b71ad0fb3886491d564.png), confirming that ![](http://latex2png.com/output//latex_e77047cadd2c9a549e8d985c7e20476b.png). For ![](http://latex2png.com/output//latex_46e30ac8a3cc4b71ad0fb3886491d564.png), images 1 needs an additional ![](http://latex2png.com/output//latex_c460c8f12789a4052bb168075aabbc1d.png) from microlensing of ![](http://latex2png.com/output//latex_d5ff624e5ade3a5bbf87506c2301433b.png), whereas images 3 and 4 require a ![](http://latex2png.com/output//latex_cdeb48ae33941a91ca1fe8d662b2c6c0.png) of ![](http://latex2png.com/output//latex_6f00341aeb245e62f957c24475a084a6.png) and ![](http://latex2png.com/output//latex_a09da2c5b88ce05397f995fc061cb330.png), the total probability for which is ![](http://latex2png.com/output//latex_ba434d2316d498e55ba2147f73a62a18.png). We conclude that the iPTF16geu flux \"anomalies\" are well within stellar microlensing predictions.\n\n### [Weighing neutrinos with the halo environment](http://arxiv.org/abs/1907.06598v1) (1907.06598v1)\n<i>Arka Banerjee, Emanuele Castorina, Francisco Villaescusa-Navarro, Travis Court, Matteo Viel</b>\n\n<h10>2019-07-15</h10>\n> Nonlinear objects like halos and voids exhibit a scale-dependent bias on linear scales in massive neutrino cosmologies. The shape of this scale-dependent bias is a unique signature of the neutrino masses, but the amplitude of the signal is generally small, of the order of ![](http://latex2png.com/output//latex_7c02a06c0e2529548d7078778bbaeaa1.png), the contribution of neutrinos to the total matter content (![](http://latex2png.com/output//latex_79e566b3fb4f5d95361f44c92e655fe4.png)). In this paper, we demonstrate for the first time how the strength of this signal can be substantially enhanced by using information about the halo environment at a range of scales. This enhancement is achieved by using certain combinations of the large scale Cold Dark Matter and total matter environments of halos, both of which are measurable from galaxy clustering and weak lensing surveys.\n\n### [Pseudo-Periodic Natural Higgs Inflation](http://arxiv.org/abs/1705.10276v2) (1705.10276v2)\n<i>I. G. Marian, N. Defenu, U. D. Jentschura, A. Trombettoni, I. Nandori</b>\n\n<h10>2017-05-29</h10>\n> Inflationary cosmology represents a well-studied framework to describe the expansion of space in the early universe, as it explains the origin of the large-scale structure of the cosmos and the isotropy of the cosmic microwave background radiation. The recent detection of the Higgs boson renewed research activities based on the assumption that the inflaton could be identified with the Higgs field. At the same time, the question whether the inflationary potential can be be extended to the electroweak scale and whether it should be necessarily chosen ad hoc in order to be physically acceptable are at the center of an intense debate. Here, we perform the slow-roll analysis of the so-called Massive Natural Inflation (MNI) model which has three adjustable parameters, the explicit mass term, a Fourier amplitude u, and a frequency parameter ![](http://latex2png.com/output//latex_a09ff5aa4faa8ac1a92a3e088b122835.png), in addition to a constant term of the potential. This theory has the advantage to present a structure of infinite non-degenerate minima and is amenable to an easy integration of high-energy modes. We show that, using PLANCK data, one can fix, in the large ![](http://latex2png.com/output//latex_a09ff5aa4faa8ac1a92a3e088b122835.png)-region, the parameters of the model in a unique way. We also demonstrate that the value for the parameters chosen at the cosmological scale does not influence the results at the electroweak scale. We argue that other models can have similar properties both at cosmological and electroweak scales, but with the MNI model one can complete the theory towards low energies and easily perform the integration of modes up to the electroweak scale, producing the correct order-of-magnitude for the Higgs mass.\n\n# <center>High Energy Astrophysical Phenomena</center> \n <hr> \n\n### [The prevalence of repeating fast radio bursts](http://arxiv.org/abs/1907.06619v1) (1907.06619v1)\n<i>Vikram Ravi</b>\n\n<h10>2019-07-15</h10>\n> Fast radio bursts are extragalactic, sub-millisecond radio impulses of unknown origin [1,2]. Their dispersion measures, which quantify the observed frequency-dependent dispersive delays in terms of free-electron column densities, significantly exceed predictions from models [3] of the Milky Way interstellar medium. The excess dispersions are likely accrued as fast radio bursts propagate through their host galaxies, gaseous galactic halos and the intergalactic medium [4,5]. Despite extensive follow-up observations of the published sample of 72 burst sources [6], only two are observed to repeat [7,8], and it is unknown whether or not the remainder are truly one-off events. Here I show that the volumetric occurrence rate of so far non-repeating fast radio bursts likely exceeds the rates of candidate cataclysmic progenitor events, and also likely exceeds the birth rates of candidate compact-object sources. This analysis is based on the high detection rate of bursts with low dispersion measures by the Canadian Hydrogen Intensity Mapping Experiment [9]. Within the existing suite of astrophysical scenarios for fast radio burst progenitors, I conclude that most observed cases originate from sources that emit several bursts over their lifetimes.\n\n### [Prompt optical emission as a signature of synchrotron radiation in  gamma-ray bursts](http://arxiv.org/abs/1904.11086v2) (1904.11086v2)\n<i>Gor Oganesyan, Lara Nava, Giancarlo Ghirlanda, Andrea Melandri, Annalisa Celotti</b>\n\n<h10>2019-04-24</h10>\n> Information on the spectral shape of prompt emission in gamma-ray bursts (GRB) is mostly available only at energies ![](http://latex2png.com/output//latex_b328eb7133309c504c2a5afeea76b815.png) keV, where the main instruments for GRB detection are sensitive. The origin of this emission is still very uncertain because of the apparent inconsistency with synchrotron radiation, which is the most obvious candidate, and the resulting need for considering less straightforward scenarios. The inclusion of data down to soft X-rays (![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png) 0.5 keV), which are available only in a small fraction of GRBs, has firmly established the common presence of a spectral break in the low-energy part of prompt spectra, and the consistency of the overall spectral shape with synchrotron radiation in the moderately fast-cooling regime, the low-energy break being identified with the cooling frequency. In this work we further extend the range of investigation down to the optical band. In particular, we test the synchrotron interpretation by directly fitting a theoretically derived synchrotron spectrum and making use of optical to gamma-ray data. Secondly, we test an alternative model that considers the presence of a black-body component at ![](http://latex2png.com/output//latex_80b2dae334617b7363258f5c8dba4404.png)keV energies, in addition to a non-thermal component that is responsible for the emission at the spectral peak (100 keV-1 MeV). We find that synchrotron radiation provides a good description of the broadband data, while models composed of a thermal and a non-thermal component require the introduction of a low-energy break in the non-thermal component in order to be consistent with optical observations. Motivated by the good quality of the synchrotron fits, we explore the physical parameter space of the emitting region. In a basic prompt emission scenario we find quite contrived solutions for the magnetic field strength (5 G ![](http://latex2png.com/output//latex_979463b2ca6edeeccb25274f15d425e3.png) G) and for the location of the region where the radiation is produced (![](http://latex2png.com/output//latex_6795be8a09c84ee33c7dd82eabe2ff0c.png) cm).\n\n### [Noise spectral estimation methods and their impact on gravitational wave  measurement of compact binary mergers](http://arxiv.org/abs/1907.06540v1) (1907.06540v1)\n<i>Katerina Chatziioannou, Carl-Johan Haster, Tyson B. Littenberg, Will M. Farr, Sudarshan Ghonge, Margaret Millhouse, James A. Clark, Neil Cornish</b>\n\n<h10>2019-07-15</h10>\n> Estimating the parameters of gravitational wave signals detected by ground-based detectors requires an understanding of the properties of the detectors' noise. In particular, the most commonly used likelihood function for gravitational wave data analysis assumes that the noise is Gaussian, stationary, and of known frequency-dependent variance. The variance of the colored Gaussian noise is used as a whitening filter on the data before computation of the likelihood function. In practice the noise variance is not known and it evolves over timescales of dozens of seconds to minutes. We study two methods for estimating this whitening filter for ground-based gravitational wave detectors with the goal of performing parameter estimation studies. The first method uses large amounts of data separated from the specific segment we wish to analyze and computes the power spectral density of the noise through the mean-median Welch method. The second method uses the same data segment as the parameter estimation analysis, which potentially includes a gravitational wave signal, and obtains the whitening filter through a fit of the power spectrum of the data in terms of a sum of splines and Lorentzians. We compare these two methods and argue that the latter is more reliable for gravitational wave parameter estimation.\n\n### [Small-scale structure of primordial black hole dark matter and its  implications for accretion](http://arxiv.org/abs/1907.06533v1) (1907.06533v1)\n<i>Gert Hütsi, Martti Raidal, Hardi Veermäe</b>\n\n<h10>2019-07-15</h10>\n> Primordial black hole (PBH) dark matter (DM) non-linear small-scale structure formation begins before the epoch of recombination due to large Poisson density fluctuations. Those small-scale effects survive until today, distinguishing physics of PBH DM structure formation from the one involving WIMP DM. We construct an analytic model for the small-scale PBH velocities which reproduces the velocity floor seen in numerical simulations, and investigate how these motions impact PBH accretion bounds at different redshifts. We find that the effect is small at the time of recombination, leaving the CMB bounds on PBH abundance unchanged. However, already at ![](http://latex2png.com/output//latex_942f056c80382551366d8f715cf76238.png) the PBH internal motion significantly reduces their accretion due to the additional ![](http://latex2png.com/output//latex_33dc930e0c671dfeb9314bd0f32d52cd.png) suppression, affecting the 21 cm bounds. Today the accretion bounds arising from dwarf galaxies or smaller PBH sub-structures are all reduced by the PBH velocity floor. We also investigate the feasibility for the PBH clusters to coherently accrete gas leading to a possible enhancement proportional to the cluster's occupation number but find this effect to be insignificant for PBH around ![](http://latex2png.com/output//latex_ad332b23ac7c68a23887bd48018d0500.png) or lighter. Those results should be reconsidered if the initial PBH distribution is not Poisson, for example, in the case of large initial PBH clustering.\n\n### [Are most Cataclysmic Variables in Globular Clusters dynamically formed?](http://arxiv.org/abs/1907.06527v1) (1907.06527v1)\n<i>Diogo Belloni, Mirek Giersz, Liliana E. Rivera Sandoval, Abbas Askar, Pawel Ciecielag</b>\n\n<h10>2019-07-15</h10>\n> We have been investigating populations of cataclysmic variables (CVs) in a set of more than 300 globular cluster (GC) models evolved with the MOCCA code. One of the main questions we have intended to answer is whether most CVs in GCs are dynamically formed or not. Contrary to what has been argued for a long time, we found that dynamical destruction of primordial CV progenitors is much stronger in GCs than dynamical formation of CVs. In particular, we found that, on average, the detectable CV population is predominantly composed of CVs formed via a typical common envelope phase (> 70 per cent). However, core-collapsed models tend to have higher fractions of bright CVs than non-core-collapsed ones, which suggests then that the formation of CVs is indeed slightly favoured through strong dynamical interactions in core-collapsed GCs, due to the high stellar densities in their cores.\n\n# <center>Instrumentation And Methods In Astrophysics</center> \n <hr> \n\n### [Noise spectral estimation methods and their impact on gravitational wave  measurement of compact binary mergers](http://arxiv.org/abs/1907.06540v1) (1907.06540v1)\n<i>Katerina Chatziioannou, Carl-Johan Haster, Tyson B. Littenberg, Will M. Farr, Sudarshan Ghonge, Margaret Millhouse, James A. Clark, Neil Cornish</b>\n\n<h10>2019-07-15</h10>\n> Estimating the parameters of gravitational wave signals detected by ground-based detectors requires an understanding of the properties of the detectors' noise. In particular, the most commonly used likelihood function for gravitational wave data analysis assumes that the noise is Gaussian, stationary, and of known frequency-dependent variance. The variance of the colored Gaussian noise is used as a whitening filter on the data before computation of the likelihood function. In practice the noise variance is not known and it evolves over timescales of dozens of seconds to minutes. We study two methods for estimating this whitening filter for ground-based gravitational wave detectors with the goal of performing parameter estimation studies. The first method uses large amounts of data separated from the specific segment we wish to analyze and computes the power spectral density of the noise through the mean-median Welch method. The second method uses the same data segment as the parameter estimation analysis, which potentially includes a gravitational wave signal, and obtains the whitening filter through a fit of the power spectrum of the data in terms of a sum of splines and Lorentzians. We compare these two methods and argue that the latter is more reliable for gravitational wave parameter estimation.\n\n### [Virtual European Solar & Planetary Access (VESPA): a Planetary Science  Virtual Observatory cornerstone](http://arxiv.org/abs/1907.06521v1) (1907.06521v1)\n<i>S. Erard, B. Cecconi, P. Le Sidaner, C. Chauvin, A. P. Rossi, M. Minin, T. Capria, S. Ivanovski, B. Schmitt, V. Genot, N. Andre, C. Marmo, A. C. Vandaele, L. Trompet, M. Scherf, R. Hueso, A. Maattanen, B. Carry, N. Achilleos, J. Soucek, D. Pisa, K. Benson, P. Fernique, E. Millour</b>\n\n<h10>2019-07-15</h10>\n> The Europlanet-2020 programme, started Sept 1st, 2015 for 4 years, includes an activity called VESPA which focuses on adapting Virtual Observatory (VO) techniques to handle Planetary Science data. The main objectives of VESPA are to facilitate searches both in big archives and in small databases, to enable data analysis by providing simple data access and on-line visualization functions, and to allow research teams to publish derived data in an interoperable environment as easily as possible. VESPA encompasses a wide scope, including surfaces, atmospheres, magnetospheres and planetary plasmas, small bodies, heliophysics, exoplanets, and spectroscopy in solid phase. This system relies in particular on standards and tools developed for the Astronomy VO (IVOA) and extends them where required to handle specificities of Solar System studies. It also aims at making the VO compatible with tools and protocols developed in different contexts, for instance GIS for planetary surfaces, or time series tools for plasma-related measurements. An essential part of the activity is to publish a significant amount of high-quality data in this system, with a focus on derived products resulting from data analysis or simulations.\n\n### [StePar: an automatic code to infer stellar atmospheric parameters](http://arxiv.org/abs/1907.06512v1) (1907.06512v1)\n<i>H. M. Tabernero, E. Marfil, D. Montes, J. I. González Hernández</b>\n\n<h10>2019-07-15</h10>\n> Context: StePar is an automatic code written in Python 3.X designed to compute the stellar atmospheric parameters Teff, log(g), [Fe/H], and of FGK-type stars by means of the EW method. This code has already been extensively tested in different spectroscopic studies of FGK-type stars with several spectrographs and against myriads of Gaia-ESO Survey UVES U580 spectra of late-type, low-mass stars as one of its thirteen pipelines.   Aims: We describe the code and test it against a library of well characterised Gaia benchmark stars. We also release the code to the community and provide the link for download.   Methods: We carried out the required EW determination of Fe I and Fe II spectral lines using the automatic tool TAME. StePar implements a grid of MARCS model atmospheres and the MOOG radiative transfer code to compute stellar atmospheric parameters by means of a Downhill Simplex minimisation algorithm.   Results: We show the results of the benchmark star test and also discuss the limitations of the EW method, and hence the code. In addition, we found a small internal scatter for the benchmark stars of 9 +- 32 K in Teff, 0.00 +- 0.07 dex in log(g), and 0.00 +- 0.03 dex in [Fe/H]. Finally, we advise against using StePar on double-lined spectroscopic binaries or spectra with R < 30,000, SNR < 20 or vsini >15 km/s as well as stars later than K4 or earlier than F6.\n\n### [Convolutional Neural Networks on the HEALPix sphere: a pixel-based  algorithm and its application to CMB data analysis](http://arxiv.org/abs/1902.04083v2) (1902.04083v2)\n<i>Nicoletta Krachmalnicoff, Maurizio Tomasi</b>\n\n<h10>2019-02-11</h10>\n> We describe a novel method for the application of Convolutional Neural Networks (CNNs) to fields defined on the sphere, using the HEALPix tessellation scheme. Specifically, We have developed a pixel-based approach to implement convolutional layers on the spherical surface, similarly to what is commonly done for CNNs in Euclidian space. The algorithm is fully integrable with existing libraries for NNs (e.g., PyTorch or TensorFlow). We present two applications: (i) recognition of handwritten digits projected on the sphere; (ii) estimation of cosmological parameter from Cosmic Microwave Background (CMB) simulated maps. We have built a simple NN architecture, consisting in four convolutional+pooling layers, and have used it for all the applications explored herein. For what concerns the handwritten digits, our CNN reaches an accuracy of about 95%, comparable with other existing spherical CNNs. For CMB applications, we have tested the CNN on the estimation of a \"mock\" parameter, defining the angular scale at which the power spectrum of a Gaussian field projected on the sphere peaks. We have estimated this parameter directly from maps, in several cases: temperature and polarization, presence of noise and partial sky coverage. In all the cases, the NN performances are comparable with those from standard spectrum-based bayesian methods. We demonstrate, for the first time, the capability of CNNs to extract information from polarization fields and to distinguish between E and B-modes. Lastly, we have applied our CNN to the estimation of the Thomson scattering optical depth at reionization (tau) from simulated CMB maps. Even without any specific optimization of the NN architecture, we reach an accuracy comparable with standard bayesian methods. This work represents a first step towards the exploitation of NNs in CMB parameter estimation and demonstrates the feasibility of our approach.\n\n### [Reconstructing solar magnetic fields from historical observations V.  Sunspot magnetic field measurements at Mount Wilson Observatory](http://arxiv.org/abs/1907.06492v1) (1907.06492v1)\n<i>Alexei A. Pevtsov, Kseniya A. Tlatova, Alexander A. Pevtsov, Elina Heikkinen, Ilpo Virtanen, Nina V. Karachik, Luca Bertello, Andrey G. Tlatov, Roger Ulrich, Kalevi Mursula</b>\n\n<h10>2019-07-15</h10>\n> Context. Systematic observations of magnetic field strength and polarity in sunspots began at Mount Wilson Observatory (MWO), USA in early 1917. Except for a few brief interruptions, this historical dataset continues till present. Aims. The sunspot field strength and polarity observations are critical in our project of reconstructing the solar magnetic field over the last hundred years. Here we provide a detailed description of the newly digitized dataset of drawings of sunspot magnetic field observations. Methods. The digitization of MWO drawings is based on a software package develope d by us. It includes a semi-automatic selection of solar limbs and other features of the drawing, and a manual entry of the time of observations, the measured field strength and other notes hand-written on each drawing. The data are preserved in a MySQL database. Results. We provide a brief history of the project and describe the results from digitizing this historical dataset. We also provide a summary of the final dataset, and describe its known limitations. Finally, we compare the sunspot magnetic field measurements with other instruments, and demonstrate that, if needed, the dataset could be continued using modern observations such as, for example, Vector Stokes Magnetograph (VSM) on Synoptic Optical Long-term Investigations of the Sun (SOLIS) platform.\n\n <br><hr> <center>Thank you for reading!<br> https://cdn.steemitimages.com/DQmbn3ovuKLM17k6aemZMrJj6iqKkYzXCYz5Qh1Fg7vPmRx/image.png <br> Don't forget to Follow and Resteem. @astrophysics <br>Keeping everyone inform.</center>",
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