August 2020 (Page 59)

AB Aur, a Rosetta stone for studies of planet formation (I): chemical study of a planet-forming disk. (arXiv:2008.00751v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Marichalar_P/0/1/0/all/0/1">Pablo Rivi&#xe8;re Marichalar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fuente_A/0/1/0/all/0/1">Asunci&#xf3;n Fuente</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gal_R/0/1/0/all/0/1">Romane Le Gal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baruteau_C/0/1/0/all/0/1">Cl&#xe9;ment Baruteau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Neri_R/0/1/0/all/0/1">Roberto Neri</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Navarro_Almaida_D/0/1/0/all/0/1">David Navarro-Almaida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Morales_S/0/1/0/all/0/1">Sandra Patricia Trevi&#xf1;o Morales</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Macias_E/0/1/0/all/0/1">Enrique Mac&#xed;as</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bachiller_R/0/1/0/all/0/1">Rafael Bachiller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Osorio_M/0/1/0/all/0/1">Mayra Osorio</a> AB Aur is a Herbig Ae star that hosts a prototypical transition disk. The disk shows a plethora of features connected with planet formation mechanisms. Understanding the physical and chemical characteristics of these features is crucial to advancing our knowledge of planet formation. We aim to characterize the gaseous disk around theRead More →

MHD accretion-ejection: jets launched by a non-isotropic accretion disk dynamo. II. A dynamo tensor defined by the disk Coriolis number. (arXiv:2008.00772v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mattia_G/0/1/0/all/0/1">Giancarlo Mattia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fendt_C/0/1/0/all/0/1">Christian Fendt</a> Astrophysical jets are launched from strongly magnetized systems that host an accretion disk surrounding a central object. Here we address the question how to generate the accretion disk magnetization and field structure required for jet launching. We continue our work from Paper I (Mattia & Fendt 2020a), considering a non-scalar accretion disk mean-field $alpha^2Omega$-dynamo in the context of large scale disk-jet simulations. We now investigate a disk dynamo that follows analytical solutions of mean-field dynamo theory, essentiallyRead More →

Fluorine in the solar neighborhood: modelling the Galactic thick and thin discs. (arXiv:2008.00812v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Grisoni_V/0/1/0/all/0/1">Valeria Grisoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Romano_D/0/1/0/all/0/1">Donatella Romano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Spitoni_E/0/1/0/all/0/1">Emanuele Spitoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matteucci_F/0/1/0/all/0/1">Francesca Matteucci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ryde_N/0/1/0/all/0/1">Nils Ryde</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jonsson_H/0/1/0/all/0/1">Henrik J&#xf6;nsson</a> We investigate the evolution of the abundance of fluorine in the Milky Way thick and thin discs by means of detailed chemical evolution models compared with recent observational data. The chemical evolution models adopted here have already been shown to fit the observed abundance patterns of CNO and $alpha$-elements as well as the metallicity distribution functions for the Galactic thick and thin disc stars. We apply them here to the study of theRead More →

Galactic extinction laws: II. Hidden in plain sight, a new interstellar absorption band at 7700 r{A} broader than any known DIB. (arXiv:2008.00834v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Apellaniz_J/0/1/0/all/0/1">J. Ma&#xed;z Apell&#xe1;niz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barba_R/0/1/0/all/0/1">R. H. Barb&#xe1;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caballero_J/0/1/0/all/0/1">J. A. Caballero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bohlin_R/0/1/0/all/0/1">R. C. Bohlin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Farina_C/0/1/0/all/0/1">C. Fari&#xf1;a</a> We have detected a broad interstellar absorption band centred close to 7700 r{A} and with a FWHM of 176.6$pm$3.9 r{A}. This is the first such absorption band detected in the optical range and is significantly wider than the numerous diffuse interstellar bands (DIBs). It remained undiscovered until now because it is partially hidden behind the A telluric band produced by O$_2$. The bandRead More →

Evidence of runaway gas cooling in the absence of supermassive black hole feedback at the epoch of cluster formation. (arXiv:2007.15660v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hlavacek_Larrondo_J/0/1/0/all/0/1">J. Hlavacek-Larrondo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rhea_C/0/1/0/all/0/1">C.L. Rhea</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Webb_T/0/1/0/all/0/1">T. Webb</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McDonald_M/0/1/0/all/0/1">M. McDonald</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Muzzin_A/0/1/0/all/0/1">A. Muzzin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wilson_G/0/1/0/all/0/1">G. Wilson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Finner_K/0/1/0/all/0/1">K. Finner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valin_F/0/1/0/all/0/1">F. Valin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bonaventura_N/0/1/0/all/0/1">N. Bonaventura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cooper_M/0/1/0/all/0/1">M. Cooper</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fabian_A/0/1/0/all/0/1">A. C. Fabian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gendron_Marsolais_M/0/1/0/all/0/1">M.-L. Gendron-Marsolais</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jee_M/0/1/0/all/0/1">M. J. Jee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lidman_C/0/1/0/all/0/1">C. Lidman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mezcua_M/0/1/0/all/0/1">M. Mezcua</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Noble_A/0/1/0/all/0/1">A. Noble</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Russell_H/0/1/0/all/0/1">H. R. Russell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Surace_J/0/1/0/all/0/1">J. Surace</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Trudeau_A/0/1/0/all/0/1">A. Trudeau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yee_H/0/1/0/all/0/1">H. K. C. Yee</a> Cosmological simulations, as well as mounting evidence from observations, have shown that supermassive black holes play a fundamental roleRead More →

Force-free magnetosphere attractors for near-horizon extreme and near-extreme limits of Kerr black hole. (arXiv:2007.15662v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Camilloni_F/0/1/0/all/0/1">F. Camilloni</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Grignani_G/0/1/0/all/0/1">G. Grignani</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Harmark_T/0/1/0/all/0/1">T. Harmark</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Oliveri_R/0/1/0/all/0/1">R. Oliveri</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Orselli_M/0/1/0/all/0/1">M. Orselli</a> We propose a new approach to find magnetically-dominated force-free magnetospheres around highly spinning black holes, relevant for models of astrophysical jets. Employing the near-horizon extreme Kerr (NHEK) limit of the Kerr black hole, any stationary, axisymmetric and regular force-free magnetosphere reduces to the same attractor solution in the NHEK limit with null electromagnetic field strength. We use this attractor solution as the universal starting point for perturbing away from the NHEK region in the extremeRead More →

Moving away from the Near-Horizon Attractor of the Extreme Kerr Force-Free Magnetosphere. (arXiv:2007.15665v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Camilloni_F/0/1/0/all/0/1">F. Camilloni</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Grignani_G/0/1/0/all/0/1">G. Grignani</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Harmark_T/0/1/0/all/0/1">T. Harmark</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Oliveri_R/0/1/0/all/0/1">R. Oliveri</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Orselli_M/0/1/0/all/0/1">M. Orselli</a> We consider force-free magnetospheres around the extreme Kerr black hole. In this case there is no known exact analytic solution to force free electrodynamics which is stationary, axisymmetric and magnetically-dominated. However, any stationary, axisymmetric and regular force-free magnetosphere in extreme Kerr black hole approaches the same attractor solution in the near-horizon extreme Kerr (NHEK) limit with null electromagnetic field. We show that by moving away from the attractor solution in the NHEK region, one finds magnetically-dominatedRead More →

Inclination Excitation of Solar System Debris Disk due to Stellar Flybys. (arXiv:2007.15666v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Moore_N/0/1/0/all/0/1">Nathaniel W. H. Moore</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_G/0/1/0/all/0/1">Gongjie Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adams_F/0/1/0/all/0/1">Fred C. Adams</a> Most stars form in clusters where relatively close encounters with other stars are common and can leave imprints on the orbital architecture of planetary systems. In this paper, we investigate the inclination excitation of debris disk particles due to such stellar encounters. We derive an analytical expression that describes inclination excitation in the hierarchical limit where the stellar flyby is distant. We then obtain numerical results for the corresponding particle inclination distribution in the non-hierarchical regime using a large ensembleRead More →

The Blue Compact Dwarf Galaxy VCC 848 Formed by Dwarf-Dwarf Merging: HI Gas, Star Formation and Numerical Simulations. (arXiv:2007.15667v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_H/0/1/0/all/0/1">Hong-Xin Zhang</a> (USTC), <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_R/0/1/0/all/0/1">Rory Smith</a> (KASI), <a href="http://arxiv.org/find/astro-ph/1/au:+Oh_S/0/1/0/all/0/1">Se-Heon Oh</a> (Sejong Univ), <a href="http://arxiv.org/find/astro-ph/1/au:+Paudel_S/0/1/0/all/0/1">Sanjaya Paudel</a> (Yonsei Univ), <a href="http://arxiv.org/find/astro-ph/1/au:+Duc_P/0/1/0/all/0/1">Pierre-Alain Duc</a> (Univ of Strasburg), <a href="http://arxiv.org/find/astro-ph/1/au:+Boselli_A/0/1/0/all/0/1">Alessandro Boselli</a> (Aix Marseille Univ), <a href="http://arxiv.org/find/astro-ph/1/au:+Cote_P/0/1/0/all/0/1">Patrick Cote</a> (NRC-HIA), <a href="http://arxiv.org/find/astro-ph/1/au:+Ferrarese_L/0/1/0/all/0/1">Laura Ferrarese</a> (NRC-HIA), <a href="http://arxiv.org/find/astro-ph/1/au:+Gao_Y/0/1/0/all/0/1">Yu Gao</a> (XMU/PMO), <a href="http://arxiv.org/find/astro-ph/1/au:+Hunter_D/0/1/0/all/0/1">Deidre A. Hunter</a> (Lowell), <a href="http://arxiv.org/find/astro-ph/1/au:+Puzia_T/0/1/0/all/0/1">Thomas H. Puzia</a> (PUC), <a href="http://arxiv.org/find/astro-ph/1/au:+Peng_E/0/1/0/all/0/1">Eric W. Peng</a> (PKU), <a href="http://arxiv.org/find/astro-ph/1/au:+Rong_Y/0/1/0/all/0/1">Yu Rong</a> (PUC), <a href="http://arxiv.org/find/astro-ph/1/au:+Shin_J/0/1/0/all/0/1">Jihye Shin</a> (KASI), <a href="http://arxiv.org/find/astro-ph/1/au:+Zhao_Y/0/1/0/all/0/1">Yinghe Zhao</a> (YNO) A clear link between a dwarf-dwarf merger event and enhanced star formation (SF) in the recentRead More →

The multi-phase ISM in the nearby composite AGN-SB galaxy NGC 4945: large (parsecs) scale mechanical heating. (arXiv:2007.15676v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bellocchi_E/0/1/0/all/0/1">Enrica Bellocchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martin_Pintado_J/0/1/0/all/0/1">Jes&#xfa;s Mart&#xed;n-Pintado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gusten_R/0/1/0/all/0/1">Rolf G&#xfc;sten</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Requena_Torres_M/0/1/0/all/0/1">Miguel Angel Requena-Torres</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harris_A/0/1/0/all/0/1">Andrew Harris</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Werf_P/0/1/0/all/0/1">Paul van der Werf</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Israel_F/0/1/0/all/0/1">Frank Israel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weiss_A/0/1/0/all/0/1">Axel Weiss</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kramer_C/0/1/0/all/0/1">Carsten Kramer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garcia_Burillo_S/0/1/0/all/0/1">Santiago Garc&#xed;a-Burillo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stutzki_J/0/1/0/all/0/1">J&#xfc;rgen Stutzki</a> We aim at carrying out a comprehensive study of the nearby composite AGN-SB galaxy, NGC 4945, using spectroscopic and photometric data from the Herschel satellite. In particular, we want to characterize the thermal structure in this galaxy by a multi-transitions analysis of the spatial distribution of the 12^CO emission at differentRead More →

Predicting the kinematic evidence of gravitational instability. (arXiv:2007.15686v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hall_C/0/1/0/all/0/1">C. Hall</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dong_R/0/1/0/all/0/1">R. Dong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Teague_R/0/1/0/all/0/1">R. Teague</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Terry_J/0/1/0/all/0/1">J. Terry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pinte_C/0/1/0/all/0/1">C. Pinte</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paneque_Carreno_T/0/1/0/all/0/1">T. Paneque-Carre&#xf1;o</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Veronesi_B/0/1/0/all/0/1">B. Veronesi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alexander_R/0/1/0/all/0/1">R. D. Alexander</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lodato_G/0/1/0/all/0/1">G. Lodato</a> Observations with the Atacama Large Millimeter/Submillimeter array (ALMA) have dramatically improved our understanding of the site of exoplanet formation: protoplanetary discs. However, many basic properties of these discs are not well-understood. The most fundamental of these is the total disc mass, which sets the mass budget for planet formation. Discs with sufficiently high masses can excite gravitational instability and drive spiral arms that are detectable with ALMA .Read More →

MHD accretion-ejection: jets launched by a non-isotropic accretion disk dynamo. I. Validation and application of selected dynamo tensorial components. (arXiv:2007.15701v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mattia_G/0/1/0/all/0/1">Giancarlo Mattia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fendt_C/0/1/0/all/0/1">Christian Fendt</a> Astrophysical jets are launched from strongly magnetized systems that host an accretion disk surrounding a central object. The origin of the jet launching magnetic field is one of the open questions for modeling the accretion-ejection process. Here we address the question how to generate the accretion disk magnetization and field structure required for jet launching. Applying the PLUTO code, we present the first resistive MHD simulations of jet launching including a non-scalar accretion disk mean-field $alpha^2Omega$-dynamo in theRead More →

X-ray evolution of the nova V959 Mon suggests a delayed ejection and a non-radiative shock. (arXiv:2007.15702v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Nelson_T/0/1/0/all/0/1">Thomas Nelson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mukai_K/0/1/0/all/0/1">Koji Mukai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chomiuk_L/0/1/0/all/0/1">Laura Chomiuk</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sokoloski_J/0/1/0/all/0/1">Jennifer L. Sokoloski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Linford_J/0/1/0/all/0/1">Justin D. Linford</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Finzell_T/0/1/0/all/0/1">Thomas Finzell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mioduszewski_A/0/1/0/all/0/1">Amy J. Mioduszewski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rupen_M/0/1/0/all/0/1">Michael P. Rupen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weston_J/0/1/0/all/0/1">Jennifer Weston</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oliveira_R/0/1/0/all/0/1">Raimundo Lopes de Oliveira</a> X-ray observations of shocked gas in novae can provide a useful probe of the dynamics of the ejecta. Here we report on X-ray observations of the nova V959 Mon, which was also detected in GeV gamma-rays with the Fermi satellite. We find that the X-ray spectra are consistent with a two-temperature plasmaRead More →

The PDR structure and kinematics around the compact HII regions S235A and S235C with [CII], [13CII], [OI] and HCO+ line profiles. (arXiv:2007.15708v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kirsanova_M/0/1/0/all/0/1">M. S. Kirsanova</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ossenkopf_Okada_V/0/1/0/all/0/1">V. Ossenkopf-Okada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_L/0/1/0/all/0/1">L. D. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boley_P/0/1/0/all/0/1">P. A. Boley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bieging_J/0/1/0/all/0/1">J. H. Bieging</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pavlyuchenkov_Y/0/1/0/all/0/1">Ya. N. Pavlyuchenkov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Luisi_M/0/1/0/all/0/1">M. Luisi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schneider_N/0/1/0/all/0/1">N. Schneider</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andersen_M/0/1/0/all/0/1">M. Andersen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Samal_M/0/1/0/all/0/1">M. R. Samal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sobolev_A/0/1/0/all/0/1">A. M. Sobolev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Buchbender_C/0/1/0/all/0/1">C. Buchbender</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aladro_R/0/1/0/all/0/1">R. Aladro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Okada_Y/0/1/0/all/0/1">Y. Okada</a> The aim of the present work is to study structure and gas kinematics in the photodissociation regions (PDRs) around the compact HII regions S235A and S235C. We observe the [CII], [13CII] and [OI]Read More →

Doppler beaming factors for white dwarfs, main sequence stars, and giant stars Limb-darkening coefficients for 3D (DA and DB) white dwarf models. (arXiv:2007.15715v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Claret_A/0/1/0/all/0/1">A. Claret</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cukanovaite_E/0/1/0/all/0/1">E. Cukanovaite</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burdge_K/0/1/0/all/0/1">K. Burdge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tremblay_P/0/1/0/all/0/1">P.-E. Tremblay</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parsons_S/0/1/0/all/0/1">S. Parsons</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marsh_T/0/1/0/all/0/1">T. R. Marsh</a> We computed Doppler beaming factors for DA, DB, and DBA white dwarf models, as well as for main sequence and giant stars covering the transmission curves of the Sloan, UBVRI, HiPERCAM, Kepler, TESS, and Gaia photometric systems. The calculations of the limb-darkening coefficients for 3D models were carried out using the least-squares method for these photometric systems. The beaming factor calculations, whichRead More →

Physics in Precision-Dependent Normal Neighborhoods. (arXiv:2007.15717v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Hoegl_B/0/1/0/all/0/1">Bruno Hoegl</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Hofmann_S/0/1/0/all/0/1">Stefan Hofmann</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Koegler_M/0/1/0/all/0/1">Maximilian Koegler</a> We introduce a procedure to determine the size and shape of normal neighborhoods in any spacetimes and their dependence on the precision of the measurements performed by arbitrary observers. As an example, we consider the Schwarzschild geometry in Riemann and Fermi normal coordinates and determine the size and shape of normal neighborhoods in the vicinity of the event horizon. Depending on the observers, normal neighborhoods extend to the event horizon and even beyond into the black hole interior. It is shown that the causal structure supported by normal neighborhoodsRead More →

Discovery of a Nearby Young Brown Dwarf Disk. (arXiv:2007.15735v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Schutte_M/0/1/0/all/0/1">M. C. Schutte</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Lawson_K/0/1/0/all/0/1">K. D. Lawson</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Wisniewski_J/0/1/0/all/0/1">J. P. Wisniewski</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Kuchner_M/0/1/0/all/0/1">M. J. Kuchner</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Silverberg_S/0/1/0/all/0/1">S. M. Silverberg</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Faherty_J/0/1/0/all/0/1">J. K. Faherty</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Gagliuffi_D/0/1/0/all/0/1">D. C. Baradlez Gagliuffi</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Kiman_R/0/1/0/all/0/1">R. Kiman</a> (4 and 5), <a href="http://arxiv.org/find/astro-ph/1/au:+Gagne_J/0/1/0/all/0/1">J. Gagn&#xe9;</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Meisner_A/0/1/0/all/0/1">A. Meisner</a> (7), <a href="http://arxiv.org/find/astro-ph/1/au:+Schneider_A/0/1/0/all/0/1">A. C. Schneider</a> (8), <a href="http://arxiv.org/find/astro-ph/1/au:+Bans_A/0/1/0/all/0/1">A. S. Bans</a> (9), <a href="http://arxiv.org/find/astro-ph/1/au:+Debes_J/0/1/0/all/0/1">J. H. Debes</a> (10), <a href="http://arxiv.org/find/astro-ph/1/au:+Kovacevic_N/0/1/0/all/0/1">N. Kovacevic</a> (11), <a href="http://arxiv.org/find/astro-ph/1/au:+Bosch_M/0/1/0/all/0/1">M. K. D. Bosch</a> (12), <a href="http://arxiv.org/find/astro-ph/1/au:+Luca_H/0/1/0/all/0/1">H. A. Durantini Luca</a> (12 and 13), <a href="http://arxiv.org/find/astro-ph/1/au:+Holden_J/0/1/0/all/0/1">J. Holden</a> (12), <a href="http://arxiv.org/find/astro-ph/1/au:+Hyogo_M/0/1/0/all/0/1">M. Hyogo</a> (12 and 14) ((1) UniversityRead More →

High-Energy Neutrinos and Gamma-Rays from Non-Relativistic Shock-Powered Transients. (arXiv:2007.15742v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Fang_K/0/1/0/all/0/1">Ke Fang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Metzger_B/0/1/0/all/0/1">Brian D. Metzger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vurm_I/0/1/0/all/0/1">Indrek Vurm</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aydi_E/0/1/0/all/0/1">Elias Aydi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chomiuk_L/0/1/0/all/0/1">Laura Chomiuk</a> Shock interaction has been argued to play a role in powering a range of optical transients, including supernovae (particularly the superluminous class), classical novae, stellar mergers, tidal disruption events, and fast blue optical transients. These same shocks can accelerate relativistic ions, generating high-energy neutrino and gamma-ray emission via hadronic pion production. The recent discovery of time-correlated optical and gamma-ray emission in classical novae has revealed the important role of radiative shocks in powering these events, enabling an unprecedented viewRead More →

Probing Reionization and Early Cosmic Enrichment with the MgII Forest. (arXiv:2007.15747v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hennawi_J/0/1/0/all/0/1">Joseph F. Hennawi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Davies_F/0/1/0/all/0/1">Frederick B. Davies</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_F/0/1/0/all/0/1">Feige Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Onorbe_J/0/1/0/all/0/1">Jose O&#xf1;orbe</a> Because the same massive stars that reionized the intergalactic medium (IGM) inevitably exploded as supernovae that polluted the Universe with metals, the history of cosmic reionization and enrichment are intimately intertwined. While the overly sensitive Ly-alpha transition completely saturates in a neutral IGM, strong low-ionization metal lines like the MgII 2796,2804 doublet will give rise to a detectable `metal-line forest’ if the metals produced during reionization (Z ~ 10^{-3}Z_sol) permeate the neutral IGM. We simulate the MgII forest forRead More →