RAS_WEB (Page 4,069)

The nature of mean-field generation in three classes of optimal dynamos. (arXiv:1911.01712v1 [physics.flu-dyn]) <a href="http://arxiv.org/find/physics/1/au:+Brandenburg_A/0/1/0/all/0/1">Axel Brandenburg</a> (Nordita), <a href="http://arxiv.org/find/physics/1/au:+Chen_L/0/1/0/all/0/1">Long Chen</a> (Durham University) In recent years, several optimal dynamos have been discovered. They minimize the magnetic energy dissipation and the critical magnetic Reynolds number or maximize the growth rate at a fixed magnetic Reynolds number. In the optimal dynamo of Willis (2012, PRL 109, 251101), we find mean-field dynamo action for planar averages. One component of the magnetic field grows exponentially while the other decays in an oscillatory fashion near onset. This behavior is different from that of an alpha^2 dynamo, where the two non-vanishing componentsRead More →

High-Energy Neutrino Astronomy: Current Status and Prospects. (arXiv:1911.01719v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Wasseige_G/0/1/0/all/0/1">Gwenha&#xeb;l de Wasseige</a> (for the IceCube and KM3NeT collaborations) In the last decade, neutrino astronomy has taken off with two major breakthroughs, the first observation of high-energy astrophysical neutrinos in 2013 and the first evidence for gamma-rays and neutrinos from a single object published in summer 2018. In this talk, we will review these important milestones as well as the other noteworthy achievements reached by the community. We will emphasize the important role of neutrino searches in the multi-messenger era and describe the current efforts carried out in the large neutrino telescope community. We willRead More →

First stars that could significantly perturb comet motion are finally found. (arXiv:1911.01735v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Wysoczanska_R/0/1/0/all/0/1">Rita Wysocza&#x144;ska</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dybczynski_P/0/1/0/all/0/1">Piotr A. Dybczy&#x144;ski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krolikowska_M/0/1/0/all/0/1">Ma&#x142;gorzata Kr&#xf3;likowska</a> Since 1950 when Oort published his paper on the structure of the cloud of comets it is believed that stars passing near this hypothetical cometary reservoir play an important role in the dynamical evolution of long period comets and injecting them into the observability region of the Solar System. The aim of this paper is to discuss two cases in which the data obtained from observations were used and stellar perturbations (of different intensity, strong case of C/2002 A3 LINEAR and weakerRead More →

iPTF14hls as a variable hyper-wind from a very massive star. (arXiv:1911.01740v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Moriya_T/0/1/0/all/0/1">Takashi J. Moriya</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mazzali_P/0/1/0/all/0/1">Paolo A. Mazzali</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pian_E/0/1/0/all/0/1">Elena Pian</a> The origin of iPTF14hls, which had Type IIP supernova-like spectra but kept bright for almost two years with little spectral evolution, is still unclear. We here propose that iPTF14hls was not a sudden outburst like supernovae but rather a long-term outflow similar to stellar winds. The properties of iPTF14hls, which are at odds with a supernova scenario, become natural when interpreted as a stellar wind with variable mass-loss rate. Based on the wind hypothesis, we estimate the mass-loss rates of iPTF14hls inRead More →

Internal magnetic fields, spin-orbit coupling, and orbital period modulation in close binary systems. (arXiv:1911.01757v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lanza_A/0/1/0/all/0/1">A. F. Lanza</a> (INAF-Catania, Italy) We introduce a new model to explain the modulation of the orbital period observed in close stellar binary systems based on an angular momentum exchange between the spin of the active component and the orbital motion. This spin-orbit coupling is not due to tides, but is produced by a non-axisymmetric component of the gravitational quadrupole moment of the active star due to a persistent non-axisymmetric internal magnetic field. The proposed mechanism easily satisfies all the energy constraints having an energy budget about 100-1000 timesRead More →

Massive stars evolution: feedbacks in low-Z environment. (arXiv:1911.01771v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ekstrom_S/0/1/0/all/0/1">Sylvia Ekstr&#xf6;m</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Meynet_G/0/1/0/all/0/1">Georges Meynet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Georgy_C/0/1/0/all/0/1">Cyril Georgy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Groh_J/0/1/0/all/0/1">Jos&#xe9; Groh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Choplin_A/0/1/0/all/0/1">Arthur Choplin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Song_H/0/1/0/all/0/1">Hanfeng Song</a> Massive stars are the drivers of the chemical evolution of dwarf galaxies. We review here the basics of massive star evolution and the specificities of stellar evolution in low-Z environment. We discuss nucleosynthetic aspects and what observations could constrain our view on the first generations of stars. Massive stars are the drivers of the chemical evolution of dwarf galaxies. We review here the basics of massive star evolution and the specificities of stellar evolution in low-Z environment. WeRead More →

r-Process and Kilonovae. (arXiv:1911.01773v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Wanajo_S/0/1/0/all/0/1">Shinya Wanajo</a> The kilonova associated with the neutron star merger GW170817 provides us with several hints to elucidate the nature of the r-process in the universe. In this article, we inspect the radioactive isotopes that powered the kilonova emission, provided that the merger ejecta consisted of material with a solar r-like abundance pattern. It is suggested that the early (1-10 days after merger) kilonova emission is mainly due to the beta-decay chain 66Ni -> 66Cu -> 66Zn, which can be the source of the steepening of the light curve at about 7 days. The late time (> 10 days)Read More →

LRP 2020 Whitepaper: The Canadian Hydrogen Observatory and Radio-transient Detector (CHORD). (arXiv:1911.01777v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Vanderlinde_K/0/1/0/all/0/1">K. Vanderlinde</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bandura_K/0/1/0/all/0/1">K. Bandura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Belostotski_L/0/1/0/all/0/1">L. Belostotski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bond_R/0/1/0/all/0/1">R. Bond</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boyle_P/0/1/0/all/0/1">P. Boyle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_J/0/1/0/all/0/1">J. Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiang_H/0/1/0/all/0/1">H. C. Chiang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dobbs_M/0/1/0/all/0/1">M. Dobbs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gaensler_B/0/1/0/all/0/1">B. Gaensler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hinshaw_G/0/1/0/all/0/1">G. Hinshaw</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kaspi_V/0/1/0/all/0/1">V. Kaspi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Landecker_T/0/1/0/all/0/1">T. Landecker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_A/0/1/0/all/0/1">A. Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masui_K/0/1/0/all/0/1">K. Masui</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mena_Parra_J/0/1/0/all/0/1">J. Mena-Parra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ng_C/0/1/0/all/0/1">C. Ng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pen_U/0/1/0/all/0/1">U. Pen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rupen_M/0/1/0/all/0/1">M. Rupen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sievers_J/0/1/0/all/0/1">J. Sievers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_K/0/1/0/all/0/1">K. Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Spekkens_K/0/1/0/all/0/1">K. Spekkens</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stairs_I/0/1/0/all/0/1">I. Stairs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Turok_N/0/1/0/all/0/1">N. Turok</a> The Canadian Hydrogen Observatory and Radio-transient Detector (CHORD) is a next-generation radio telescope, proposed for construction to start immediately. CHORD is aRead More →

Escaping from the herd of white elephants. (arXiv:1911.01813v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Noordam_J/0/1/0/all/0/1">Jan Noordam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grange_Y/0/1/0/all/0/1">Yan Grange</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Teuben_P/0/1/0/all/0/1">Peter Teuben</a> About 60 ADASS participants discussed the evolving roles of users, developers, and managers of astronomical data reduction software. Special emphasis was placed on the role of the user in the era of Big Data. Is it really inevitable that the increasingly ignorant user will just have to be satisfied with the standard products from data processing centres? About 60 ADASS participants discussed the evolving roles of users, developers, and managers of astronomical data reduction software. Special emphasis was placed on the role of the user in theRead More →

General relativistic magnetohydrodynamic dynamo in thick accretion disks: fully nonlinear simulations. (arXiv:1911.01838v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Tomei_N/0/1/0/all/0/1">N. Tomei</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zanna_L/0/1/0/all/0/1">L. Del Zanna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bugli_M/0/1/0/all/0/1">M. Bugli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bucciantini_N/0/1/0/all/0/1">N. Bucciantini</a> The recent imaging of the M87 black hole at millimeter wavelengths by the Event Horizon Telescope (EHT) collaboration has triggered a renewed interest in numerical models for the accretion of magnetized plasma in the regime of general relativistic magnetohydrodynamics (GRMHD). Here non-ideal simulations, including both the resistive effects and, above all, the mean-field dynamo action due to sub-scale, unresolved turbulence, are applied for the first time to such systems in the fully nonlinear regime. Combined with the differential rotationRead More →

Active Galactic Nuclei with Ultra-fast Outflows Monitoring Project: The Broad-line Region of Mrk 79 as a Disk Wind. (arXiv:1911.01852v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_K/0/1/0/all/0/1">Kai-Xing Lu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bai_J/0/1/0/all/0/1">Jin-Ming Bai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_Z/0/1/0/all/0/1">Zhi-Xiang Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Du_P/0/1/0/all/0/1">Pu Du</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hu_C/0/1/0/all/0/1">Chen Hu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kim_M/0/1/0/all/0/1">Minjin Kim</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_J/0/1/0/all/0/1">Jian-Min Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ho_L/0/1/0/all/0/1">Luis C. Ho</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_Y/0/1/0/all/0/1">Yan-Rong Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bian_W/0/1/0/all/0/1">Wei-Hao Bian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yuan_Y/0/1/0/all/0/1">Ye-Fei Yuan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xiao_M/0/1/0/all/0/1">Ming Xiao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feng_H/0/1/0/all/0/1">Hai-Cheng Feng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_J/0/1/0/all/0/1">Jian-Guo Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xu_L/0/1/0/all/0/1">Liang Xu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ding_X/0/1/0/all/0/1">Xu Ding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yu_X/0/1/0/all/0/1">Xiao-Guang Yu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xin_Y/0/1/0/all/0/1">Yu-Xin Xin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ye_K/0/1/0/all/0/1">Kai Ye</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_C/0/1/0/all/0/1">Chuan-Jun Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lun_B/0/1/0/all/0/1">Bao-Li Lun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_J/0/1/0/all/0/1">Ju-Jia Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_X/0/1/0/all/0/1">Xi-Liang Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ji_K/0/1/0/all/0/1">Kai-Fan Ji</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fan_Y/0/1/0/all/0/1">Yu-Feng Fan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chang_L/0/1/0/all/0/1">Liang Chang</a> We developed a spectroscopic monitoring projectRead More →

Star density profiles of six old star clusters in the Large Magellanic Cloud. (arXiv:1911.01928v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lanzoni_B/0/1/0/all/0/1">B. Lanzoni</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Ferraro_F/0/1/0/all/0/1">F. R. Ferraro</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Dalessandro_E/0/1/0/all/0/1">E. Dalessandro</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Cadelano_M/0/1/0/all/0/1">M. Cadelano</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Pallanca_C/0/1/0/all/0/1">C. Pallanca</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Raso_S/0/1/0/all/0/1">S. Raso</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Mucciarelli_A/0/1/0/all/0/1">A. Mucciarelli</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Beccari_G/0/1/0/all/0/1">G. Beccari</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Focardi_P/0/1/0/all/0/1">P. Focardi</a> (1)- (1 Bologna University, Italy, (2) INAF-OAS, Bologna, Italy, (3) ESO, Germany) We used resolved star counts from Hubble Space Telescope images to determine the center of gravity and the projected density profiles of 6 old globular clusters in the Large Magellanic Cloud (LMC), namely NGC 1466, NGC 1841, NGC 1898, NGC 2210, NGCRead More →

Core mass — halo mass relation of bosonic and fermionic dark matter halos harbouring a supermassive black hole. (arXiv:1911.01937v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Chavanis_P/0/1/0/all/0/1">Pierre-Henri Chavanis</a> We study the core mass — halo mass relation of bosonic dark matter halos, in the form of self-gravitating Bose-Einstein condensates, harbouring a supermassive black hole. We use the “velocity dispersion tracing” relation according to which the velocity dispersion in the core $v_c^2sim GM_c/R_c$ is of the same order as the velocity dispersion in the halo $v_h^2sim GM_h/r_h$ (this relation can be justified from thermodynamical arguments) and the approximate analytical mass-radius relation of the quantum core in the presence of a centralRead More →

A sample of GRB radio afterglows inconsistent with the standard jet model. (arXiv:1911.01938v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kangas_T/0/1/0/all/0/1">Tuomas Kangas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fruchter_A/0/1/0/all/0/1">Andrew Fruchter</a> We present a sample of 15 gamma-ray burst (GRB) afterglow light curves at radio frequencies, and compare them to the X-ray and/or optical properties of the afterglows and to the predictions of the standard jet/fireball model. Our sample has been chosen so that each afterglow exhibits a jet break at some frequency, usually X-ray. We examine the late-time decline of each burst in the radio and in the X-ray, and attempt to fit an analytical model based on the conventional GRB afterglow equations to eachRead More →

Unveiling the merger dynamics of the most massive MaDCoWS cluster at $z = 1.2$ from a multi-wavelength mapping of its intracluster medium properties. (arXiv:1911.00560v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ruppin_F/0/1/0/all/0/1">F. Ruppin</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:+Brodwin_M/0/1/0/all/0/1">M. Brodwin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adam_R/0/1/0/all/0/1">R. Adam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ade_P/0/1/0/all/0/1">P. Ade</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andre_P/0/1/0/all/0/1">P. Andr&#xe9;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andrianasolo_A/0/1/0/all/0/1">A. Andrianasolo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arnaud_M/0/1/0/all/0/1">M. Arnaud</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aussel_H/0/1/0/all/0/1">H. Aussel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bartalucci_I/0/1/0/all/0/1">I. Bartalucci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bautz_M/0/1/0/all/0/1">M. W. Bautz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beelen_A/0/1/0/all/0/1">A. Beelen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benoit_A/0/1/0/all/0/1">A. Beno&#xee;t</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bideaud_A/0/1/0/all/0/1">A. Bideaud</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bourrion_O/0/1/0/all/0/1">O. Bourrion</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Calvo_M/0/1/0/all/0/1">M. Calvo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Catalano_A/0/1/0/all/0/1">A. Catalano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Comis_B/0/1/0/all/0/1">B. Comis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Decker_B/0/1/0/all/0/1">B. Decker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Petris_M/0/1/0/all/0/1">M. De Petris</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Desert_F/0/1/0/all/0/1">F.-X. D&#xe9;sert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Doyle_S/0/1/0/all/0/1">S. Doyle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Driessen_E/0/1/0/all/0/1">E. F. C. Driessen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eisenhardt_P/0/1/0/all/0/1">P. R. M. Eisenhardt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gomez_A/0/1/0/all/0/1">A.Read More →

Infrared dynamics of a light scalar field in de Sitter. (arXiv:1911.00564v1 [hep-th]) <a href="http://arxiv.org/find/hep-th/1/au:+Mirbabayi_M/0/1/0/all/0/1">Mehrdad Mirbabayi</a> Inertial observers in de Sitter are surrounded by a horizon and see thermal fluctuations. To them, a massless scalar field appears to follow a random motion, but any attractive potential, no matter how weak, will eventually stabilize the field. We study this thermalization process in the static patch—the spacetime region accessible to an individual observer—via a truncation to the low frequency spectrum. We focus on the distribution of the field averaged over a subhorizon region. At time scales much longer than the inverse temperature, we find the evolution to beRead More →

SDSS-IV MaNGA: Variations in the N/O — O/H relation bias metallicity gradient measurements. (arXiv:1911.00581v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Schaefer_A/0/1/0/all/0/1">Adam L. Schaefer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tremont_C/0/1/0/all/0/1">Christy Tremont</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Belfiore_F/0/1/0/all/0/1">Francesco Belfiore</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pace_Z/0/1/0/all/0/1">Zachary Pace</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bershady_M/0/1/0/all/0/1">Matthew A. Bershady</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andrews_B/0/1/0/all/0/1">Brett H. Andrews</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Drory_N/0/1/0/all/0/1">Niv Drory</a> In this paper we use strong line calibrations of N/O and O/H in MaNGA spaxel data to explore the systematics introduced by variations in N/O on various strong-line metallicity diagnostics. We find radial variations in N/O at fixed O/H which correlate with total galaxy stellar-mass; and which can induce $sim 40 %$ systematic uncertainties in oxygen abundance gradients when nitrogen-dependent abundance calibrations are used. Empirically, weRead More →

Observational Investigation of the 2013 Near-Earth Encounter by Asteroid (367943) Duende. (arXiv:1911.00609v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Moskovitz_N/0/1/0/all/0/1">Nicholas Moskovitz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benson_C/0/1/0/all/0/1">Conor Benson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Scheeres_D/0/1/0/all/0/1">Daniel Scheeres</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Endicott_T/0/1/0/all/0/1">Thomas Endicott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Polishook_D/0/1/0/all/0/1">David Polishook</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Binzel_R/0/1/0/all/0/1">Richard Binzel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DeMeo_F/0/1/0/all/0/1">Francesca DeMeo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ryan_W/0/1/0/all/0/1">William Ryan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ryan_E/0/1/0/all/0/1">Eileen Ryan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Willman_M/0/1/0/all/0/1">Mark Willman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hergenrother_C/0/1/0/all/0/1">Carl Hergenrother</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Verneer_A/0/1/0/all/0/1">Arie Verneer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lister_T/0/1/0/all/0/1">Tim Lister</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Birtwhistle_P/0/1/0/all/0/1">Peter Birtwhistle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sickafoose_A/0/1/0/all/0/1">Amanda Sickafoose</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nagayama_T/0/1/0/all/0/1">Takahiro Nagayama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gilmore_A/0/1/0/all/0/1">Alan Gilmore</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kilmartin_P/0/1/0/all/0/1">Pamela Kilmartin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bennechi_S/0/1/0/all/0/1">Susan Bennechi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sheppard_S/0/1/0/all/0/1">Scott Sheppard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marchis_F/0/1/0/all/0/1">Franck Marchis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Augusteijn_T/0/1/0/all/0/1">Thomas Augusteijn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smirnova_O/0/1/0/all/0/1">Olesja Smirnova</a> On 15 February 2013, the asteroid 367943 Duende (2012 DA14) experienced a near-Earth encounter at an altitude of 27,700 km or 4.2 EarthRead More →

Fragmentation in a Primordial Accretion Flow. (arXiv:1911.00610v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Liao_W/0/1/0/all/0/1">Wei-Ting Liao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Turk_M/0/1/0/all/0/1">Matthew Turk</a> Under rapid cooling from molecular hydrogen, the accretion disks around Population III (PopIII) stars are believed to fragment, resulting in multiple accreting cores. In this paper, we build a theoretical framework for calculating the optical depth of H$_2$ ro-vibrational line cooling based on the vertical structure in these accretion disks. Applying this physically motivated prescription for the optical depth, we find that cooling in the inner disk with $r lesssim 10 {rm AU}$ is attenuated significantly as a result of high surface density; $PdV$ heating becomes more efficient than cooling, whichRead More →