RAS_WEB (Page 2,758)

Hinode/EIS measurements of active region magnetic fields. (arXiv:2008.03532v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Landi_E/0/1/0/all/0/1">E. Landi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hutton_R/0/1/0/all/0/1">R. Hutton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brage_T/0/1/0/all/0/1">T. Brage</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_W/0/1/0/all/0/1">W. Li</a> The present work illustrates the potential of a new diagnostic technique that allows the measurement of the coronal magnetic field strength in solar active regions utilizing a handful of bright ion[Fe x] and ion[Fe xi] lines commonly observed by the Hinode/EIS high-resolution spectrometer. The importance of this new diagnostic technique lies in two basic facts: 1) the coronal magnetic field is probably the most important quantity in coronal physics, as it is at the heart of the processes regulating Space Weather and the propertiesRead More →

On the Influence of the Ionization-Recombination Processes on Hydrogen Plasma Polytropic Index. (arXiv:2008.03565v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mishonov_T/0/1/0/all/0/1">Todor M. Mishonov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dimitrova_I/0/1/0/all/0/1">Iglika M. Dimitrova</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Varonov_A/0/1/0/all/0/1">Albert M. Varonov</a> The polytropic (adiabatic) index for pure hydrogen plasma is analytically calculated as function of reciprocal temperature and degree of ionization. Additionally, the polytropic index is graphically represented as a function of temperature and density. It is concluded that the partially ionized hydrogen plasma cannot be exactly polytropic. The calculated deviations from the mono-atomic value 5/3 are of order of the determined by the analysis of spectroscopic observations. As the solar coronal plasma is in some approximation hydrogen plasma, itRead More →

First in-situ detection of the CN radical in comets and evidence for a distributed source. (arXiv:2008.03576v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hanni_N/0/1/0/all/0/1">Nora H&#xe4;nni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Altwegg_K/0/1/0/all/0/1">Kathrin Altwegg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pestoni_B/0/1/0/all/0/1">Boris Pestoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rubin_M/0/1/0/all/0/1">Martin Rubin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schroeder_I/0/1/0/all/0/1">Isaac Schroeder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schuhmann_M/0/1/0/all/0/1">Markus Schuhmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wampfler_S/0/1/0/all/0/1">Susanne Wampfler</a> Although the debate regarding the origin of the cyano (CN) radical in comets has been ongoing for many decades, it has yielded no definitive answer to date. CN could previously only be studied remotely, strongly hampering efforts to constrain its origin because of very limited spatial information. Thanks to the European Space Agency’s Rosetta spacecraft, which orbited comet 67P/Churyumov-Gerasimenko for two years, we can investigate, for theRead More →

Modeling the past and future activity of the Halleyids meteor showers. (arXiv:2008.03589v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Egal_A/0/1/0/all/0/1">Auriane Egal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wiegert_P/0/1/0/all/0/1">Paul Wiegert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_P/0/1/0/all/0/1">Peter G. Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Campbell_Brown_M/0/1/0/all/0/1">Margaret Campbell-Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vida_D/0/1/0/all/0/1">Denis Vida</a> We present a new numerical model of the eta-Aquariid and Orionid meteor showers. The model investigates the origin, variability and age of the eta-Aquariid and Orionid apparitions from 1985 to the present day, in order to forecast their activity over the next several decades. Through the numerical integration of millions of simulated meteoroids and a custom-made particle weighting scheme, we model the characteristics of every eta-Aquariid and Orionid apparition between 1985 and 2050. The modeled showersRead More →

Water worlds in N-body simulations with fragmentation in systems without gaseous giants. (arXiv:2008.03594v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Dugaro_A/0/1/0/all/0/1">Agust&#xed;n Dugaro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Elia_G/0/1/0/all/0/1">Gonzalo C. de El&#xed;a</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Darriba_L/0/1/0/all/0/1">Luciano A. Darriba</a> We analyze the formation and evolution of terrestrial-like planets around solar-type stars in the absence of gaseous giants. In particular, we focus on the physical and dynamical properties of those that survive in the system’s Habitable Zone (HZ). This study is based on a comparative study between N-body simulations that include fragmentation and others that consider all collisions as perfect mergers. We use an N-body code, presented in a previous paper, that allows planetary fragmentation. We carry out threeRead More →

Exploring the stellar age distribution of the Milky Way Bulge using APOGEE. (arXiv:2008.03603v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hasselquist_S/0/1/0/all/0/1">Sten Hasselquist</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zasowski_G/0/1/0/all/0/1">Gail Zasowski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feuillet_D/0/1/0/all/0/1">Diane K. Feuillet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schultheis_M/0/1/0/all/0/1">Mathias Schultheis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nataf_D/0/1/0/all/0/1">David M. Nataf</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anguiano_B/0/1/0/all/0/1">Borja Anguiano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beaton_R/0/1/0/all/0/1">Rachael L. Beaton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beers_T/0/1/0/all/0/1">Timothy C. Beers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cohen_R/0/1/0/all/0/1">Roger E. Cohen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cunha_K/0/1/0/all/0/1">Katia Cunha</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fernandez_Trincado_J/0/1/0/all/0/1">Jos&#xe9; G. Fern&#xe1;ndez-Trincado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garcia_Hernandez_D/0/1/0/all/0/1">D. A. Garc&#xed;a-Hern&#xe1;ndez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Geisler_D/0/1/0/all/0/1">Doug Geisler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Holtzman_J/0/1/0/all/0/1">Jon A. Holtzman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Johnson_J/0/1/0/all/0/1">Jennifer Johnson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lane_R/0/1/0/all/0/1">Richard R. Lane</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Majewski_S/0/1/0/all/0/1">Steven R. Majewski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bidin_C/0/1/0/all/0/1">Christian Moni Bidin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nitschelm_C/0/1/0/all/0/1">Christian Nitschelm</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roman_Lopes_A/0/1/0/all/0/1">Alexandre Roman-Lopes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schiavon_R/0/1/0/all/0/1">Ricardo Schiavon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_V/0/1/0/all/0/1">Verne V. Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sobeck_J/0/1/0/all/0/1">Jennifer Sobeck</a> We present stellar age distributions of the Milky Way (MW)Read More →

Inevitable consequences of ion-neutral damping of intermediate MHD waves in Sun-like stars. (arXiv:2008.03607v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Judge_P/0/1/0/all/0/1">Philip G. Judge</a> In the context of the solar atmosphere, we re-examine the role of of neutral and ionized species in dissipating the ordered energy of intermediate-mode MHD waves into heat. We solve conservation equations for the hydrodynamics and for hydrogen and helium ionization stages, along closed tubes of magnetic field. First, we examine the evolution of coronal plasma under conditions where coronal heating has abruptly ceased. We find that cool ($< 10^5$K) structures are formed lasting for several hours. MHD waves of modest amplitude can heat the plasma throughRead More →

An Independent Analysis of the Six Recently Claimed Exomoon Candidates. (arXiv:2008.03613v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kipping_D/0/1/0/all/0/1">David Kipping</a> It has been recently claimed that KOIs-268.01, 303.01, 1888.01, 1925.01, 2728.01 & 3320.01 are exomoon candidates, based on an analysis of their transit timing. Here, we perform an independent investigation, which is framed in terms of three questions: 1) Are there significant excess TTVs? 2) Is there a significant periodic TTV? 3) Is there evidence for a non-zero moon mass? We applied rigorous statistical methods to these questions alongside a re-analysis of the Kepler photometry and find that none of the KOIs satisfy these three tests. Specifically, KOIs-268.01 & 3220.01Read More →

Multi-Wavelength Constraints on the Outflow Properties of the Extremely Bright Millisecond Radio Bursts from the Galactic Magnetar SGR 1935+2154. (arXiv:2008.03634v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Yamasaki_S/0/1/0/all/0/1">Shotaro Yamasaki</a> (HUJI), <a href="http://arxiv.org/find/astro-ph/1/au:+Kashiyama_K/0/1/0/all/0/1">Kazumi Kashiyama</a> (U. Tokyo), <a href="http://arxiv.org/find/astro-ph/1/au:+Murase_K/0/1/0/all/0/1">Kohta Murase</a> (PSU) Recently, a bright coherent radio burst with millisecond duration, reminiscent of cosmological fast radio bursts (FRBs), was co-detected with an anomalously-hard X-ray burst from a Galactic magnetar SGR 1935$+$2154. We investigate the possibility that the event was triggered by a deposition of a magnetic energy in a localized region of the magnetosphere, thereby producing a so-called trapped fireball (FB) and simultaneously launching relativistic outflows. We show that the thermal component ofRead More →

New Cutoff Frequency for Torsional Alfv’en Waves Propagating along Wide Solar Magnetic flux Tubes. (arXiv:2008.03653v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Routh_S/0/1/0/all/0/1">Swati Routh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Musielak_Z/0/1/0/all/0/1">Z.E. Musielak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sundar_M/0/1/0/all/0/1">M.N. Sundar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_S/0/1/0/all/0/1">Sai Sravanthi Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charan_S/0/1/0/all/0/1">Sree Charan</a> An isolated, isothermal, and wide magnetic flux tube embedded either in the solar chromosphere or in the lower solar corona is considered, and the propagation of linear torsional Alfv’en waves is investigated. It is shown that the wideness of the tube leads to a new cutoff frequency, which is a local quantity that gives the conditions for the wave propagation at different atmospheric heights. The cutoff is used to establish the ranges ofRead More →

Simulations of orbital debris clouds due to breakup events and their characterisation using the Murchison Widefield Array radio telescope. (arXiv:2008.03657v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Joubert_W/0/1/0/all/0/1">Wynand Joubert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tingay_S/0/1/0/all/0/1">Steven Tingay</a> In this paper we consider the use of wide field of view radar sensors such as the Murchison Widefield Array (MWA), a low frequency radio telescope designed for astrophysics and cosmology, for rapid response observations of the debris clouds produced by collisions between objects in Earth orbit. With an increasing density of objects in Low Earth Orbit, including legacy assets used by the astronomy community over decades, the risk of new debris clouds forming is also increasing. TheRead More →

Searching for the radio remnants of short duration gamma-ray bursts. (arXiv:2008.03659v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ricci_R/0/1/0/all/0/1">Roberto Ricci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Troja_E/0/1/0/all/0/1">Eleonora Troja</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bruni_G/0/1/0/all/0/1">Gabriele Bruni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matsumoto_T/0/1/0/all/0/1">Tatsuya Matsumoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piro_L/0/1/0/all/0/1">Luigi Piro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+OConnor_B/0/1/0/all/0/1">Brendan O&#x27;Connor</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piran_T/0/1/0/all/0/1">Tsvi Piran</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Navaieelavasani_N/0/1/0/all/0/1">Niloofar Navaieelavasani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Corsi_A/0/1/0/all/0/1">Alessandra Corsi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giacomazzo_B/0/1/0/all/0/1">Bruno Giacomazzo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wieringa_M/0/1/0/all/0/1">Mark H. Wieringa</a> Neutron star mergers produce a substantial amount of fast-moving ejecta, expanding outwardly for years after the merger. The interaction of these ejecta with the surrounding medium may produce a weak isotropic radio remnant, detectable in relatively nearby events. We use late-time radio observations of short duration gamma-ray bursts (sGRBs) to constrain this model. Two samples of events were studied:Read More →

Discovery of state transition behaviors in PSR J1124–5916. (arXiv:2008.03671v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ge_M/0/1/0/all/0/1">M. Y. Ge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yuan_J/0/1/0/all/0/1">J. P. Yuan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_F/0/1/0/all/0/1">F. J. Lu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tong_H/0/1/0/all/0/1">H. Tong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhou_S/0/1/0/all/0/1">S. Q. Zhou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yan_L/0/1/0/all/0/1">L. L. Yan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_L/0/1/0/all/0/1">L. J. Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tuo_Y/0/1/0/all/0/1">Y. L.Tuo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_X/0/1/0/all/0/1">X. F. Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Song_L/0/1/0/all/0/1">L. M. Song</a> With the twelve-year long observations by {sl Fermi}-LAT, we discover two pairs of spin-down state transitions of PSR J1124–5916, making it the second young pulsar detected to have such behaviors. PSR J1124–5916 shows mainly two states according to its spin-down rate evolution, the normal spin-down state and the low spin-down state. In about 80% of the observationRead More →

The clustering of gamma-ray bursts in the Hercules–Corona Borealis Great Wall: the largest structure in the Universe?. (arXiv:2008.03679v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Horvath_I/0/1/0/all/0/1">I. Horvath</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Szecsi_D/0/1/0/all/0/1">D. Sz&#xe9;csi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hakkila_J/0/1/0/all/0/1">J. Hakkila</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Szabo_A/0/1/0/all/0/1">&#xc1;. Szab&#xf3;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Racz_I/0/1/0/all/0/1">I. I. Racz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toth_L/0/1/0/all/0/1">L. V. T&#xf3;th</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pinter_S/0/1/0/all/0/1">S. Pint&#xe9;r</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bagoly_Z/0/1/0/all/0/1">Z. Bagoly</a> The Hercules–Corona Borealis Great Wall is a statistically significant clustering of gamma-ray bursts around redshift 2. Motivated by recent theoretical results indicating that a maximal Universal structure size may indeed coincide with its estimated size (2$-$3,Gpc), we reexamine the question of this Great Wall’s existence from both observational and theoretical perspectives. Our statistical analyses confirm the clustering’s presence in theRead More →

Vibrationally excited HC3N emission in NGC1068: Tracing the recent star formation in the starburst ring. (arXiv:2008.03693v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Villas_F/0/1/0/all/0/1">Fernando Rico Villas</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:+Gonzalez_Alfonso_E/0/1/0/all/0/1">Eduardo Gonz&#xe1;lez-Alfonso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rivilla_V/0/1/0/all/0/1">Victor M. Rivilla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martin_S/0/1/0/all/0/1">Sergio Mart&#xed;n</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:+Jimenez_Serra_I/0/1/0/all/0/1">Izaskun Jim&#xe9;nez-Serra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_Garcia_M/0/1/0/all/0/1">Mar&#xed;a S&#xe1;nchez-Garc&#xed;a</a> Using ALMA data, we have studied the HC$_3$N and continuum emission in the starburst ring (SB ring) and the circumnuclear disc (CND) of the SB/AGN composite galaxy NGC 1068. We have detected emission from vibrationally excited HC$_3$N (HC$_3$N*) only towards one star-forming region of the SB ring. Remarkably, HC$_3$N* was not detected towards the CND despite its large HC$_3$N $v=0$ column density.Read More →

Magnetic moments of the octet, low-lying charm, and low-lying bottom baryons in a nuclear medium. (arXiv:2008.03724v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Tsushima_K/0/1/0/all/0/1">Kazuo Tsushima</a> We study the magnetic moments of the octet, low-lying charm, and low-lying bottom baryons with nonzero light quarks in symmetric nuclear matter. This is the first study of estimating the medium modifications of magnetic moments for these low-lying charm and bottom baryons. We study the magnetic moments of the octet, low-lying charm, and low-lying bottom baryons with nonzero light quarks in symmetric nuclear matter. This is the first study of estimating the medium modifications of magnetic moments for these low-lying charm and bottom baryons. http://arxiv.org/icons/sfx.gifRead More →

A Radio Pinwheel Emanating from WR147. (arXiv:2008.03725v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rodriguez_L/0/1/0/all/0/1">Luis F. Rodr&#xed;guez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arthur_J/0/1/0/all/0/1">Jane Arthur</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Montes_G/0/1/0/all/0/1">Gabriela Montes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carrasco_Gonzalez_C/0/1/0/all/0/1">Carlos Carrasco-Gonz&#xe1;lez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toala_J/0/1/0/all/0/1">Jes&#xfa;s A. Toal&#xe1;</a> Wolf-Rayet (WR) stars are evolved massive stars, presumably on their way to becoming supernova. They are characterized by high luminosities and fast and dense stellar winds. We have detected signs of a radio continuum pinwheel associated with WR147, a nitrogen-rich WR star with spectral subtype WN8. These structures are known around a handful of late-type carbon-rich WR stars with massive companions were the dust formed at the zone where the two winds collide produces a plume of dense gas andRead More →

Differing Enceladean ocean circulation and ice shell geometries driven by tidal heating in the ice versus the core. (arXiv:2008.03764v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kang_W/0/1/0/all/0/1">Wanying Kang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bire_S/0/1/0/all/0/1">Suyash Bire</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Campin_J/0/1/0/all/0/1">Jean-Michel Campin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sotin_C/0/1/0/all/0/1">Christophe Sotin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+German_C/0/1/0/all/0/1">Christopher German</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Thurnherr_A/0/1/0/all/0/1">Andreas Thurnherr</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marshall_J/0/1/0/all/0/1">John Marshall</a> Beneath the icy shell encasing Enceladus, a small icy moon of Saturn, a global ocean of liquid water ejects geyser-like plumes into space through fissures in the ice, making it an attractive place to investigate habitability and to search for extraterrestrial life. The existence of an ocean on Enceladus has been attributed to the heat generated in dissipative processes associated with deformation by tidalRead More →

13 Years of P Cygni Spectropolarimetry: Investigating Mass-loss Through H$alpha$, Periodicity, and Ellipticity. (arXiv:2008.03777v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Gootkin_K/0/1/0/all/0/1">Keyan Gootkin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dorn_Wallenstein_T/0/1/0/all/0/1">Trevor Dorn-Wallenstein</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lomax_J/0/1/0/all/0/1">Jamie R. Lomax</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eadie_G/0/1/0/all/0/1">Gwendolyn Eadie</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Levesque_E/0/1/0/all/0/1">Emily M. Levesque</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Babler_B/0/1/0/all/0/1">Brian Babler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hoffman_J/0/1/0/all/0/1">Jennifer L. Hoffman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Meade_M/0/1/0/all/0/1">Marilyn R. Meade</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nordsieck_K/0/1/0/all/0/1">Kenneth Nordsieck</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wisniewski_J/0/1/0/all/0/1">John P. Wisniewski</a> We report on over 13 years of optical and near-ultraviolet spectropolarimetric observations of the famous Luminous Blue Variable (LBV), P Cygni. LBVs are a critical transitional phase in the lives of the most massive stars, and achieve the largest mass-loss rates of any group of stars. Using spectropolarimetry, we are able to learn about theRead More →

Magnetorotational core collapse of possible GRB progenitors. II. Formation of protomagnetars and collapsars. (arXiv:2008.03779v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Aloy_M/0/1/0/all/0/1">Miguel-&#xc1;ngel Aloy</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Obergaulinger_M/0/1/0/all/0/1">Martin Obergaulinger</a> (1 and 2) ((1) U. Valencia, (2) TU Darmstadt) We assess the variance of the post-collapse evolution remnants of compact, massive, low-metallicity stars, under small changes in the degrees of rotation and magnetic field of selected pre-supernova cores. These stellar models are commonly considered progenitors of long gamma-ray bursts. The fate of the proto-neutron star (PNS) formed after collapse, whose mass may continuously grow due to accretion, critically depends on the poloidal magnetic field strength at bounce. Should the poloidal magnetic field beRead More →