RAS_WEB (Page 2,205)

Quasi-periodic dipping in the ultraluminous X-ray source, NGC 247 ULX-1. (arXiv:2104.11163v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Alston_W/0/1/0/all/0/1">W. N. Alston</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pinto_C/0/1/0/all/0/1">C. Pinto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barret_D/0/1/0/all/0/1">D. Barret</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DAi_A/0/1/0/all/0/1">A. D&#x27;Ai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Santo_M/0/1/0/all/0/1">M. Del Santo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Earnshaw_H/0/1/0/all/0/1">H. Earnshaw</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:+Fuerst_F/0/1/0/all/0/1">F. Fuerst</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kara_E/0/1/0/all/0/1">E. Kara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kosec_P/0/1/0/all/0/1">P. Kosec</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Middleton_M/0/1/0/all/0/1">M. J. Middleton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parker_M/0/1/0/all/0/1">M. L. Parker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pintore_F/0/1/0/all/0/1">F. Pintore</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Robba_A/0/1/0/all/0/1">A. Robba</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roberts_T/0/1/0/all/0/1">T. P. Roberts</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sathyaprakash_R/0/1/0/all/0/1">R. Sathyaprakash</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Walton_D/0/1/0/all/0/1">D. Walton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ambrosi_E/0/1/0/all/0/1">E. Ambrosi</a> Most ultraluminous X-ray sources (ULXs) are believed to be stellar mass black holes or neutron stars accreting beyond the Eddington limit. Determining the nature of the compact object and the accretion modeRead More →

Cosmological radiation density with non-standard neutrino-electron interactions. (arXiv:2105.08168v1 [hep-ph] CROSS LISTED) <a href="http://arxiv.org/find/hep-ph/1/au:+Salas_P/0/1/0/all/0/1">Pablo F. de Salas</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Gariazzo_S/0/1/0/all/0/1">Stefano Gariazzo</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Martinez_Mirave_P/0/1/0/all/0/1">Pablo Mart&#xed;nez-Mirav&#xe9;</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Pastor_S/0/1/0/all/0/1">Sergio Pastor</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Tortola_M/0/1/0/all/0/1">Mariam T&#xf3;rtola</a> Neutrino non-standard interactions (NSI) with electrons are known to alter the picture of neutrino decoupling from the cosmic plasma. NSI modify both flavour oscillations through matter effects, and the annihilation and scattering between neutrinos and electrons and positrons in the thermal plasma. In view of the forthcoming cosmological observations, we perform a precision study of the impact of non-universal and flavour-changing NSI on the effective number of neutrinos, $N_{eff}$. We present the variation of $N_{eff}$ arising fromRead More →

NGTS-19b : A high mass transiting brown dwarf in a 17-day eccentric orbit. (arXiv:2105.08574v2 [astro-ph.EP] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Acton_J/0/1/0/all/0/1">Jack S. Acton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Goad_M/0/1/0/all/0/1">Michael R. Goad</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burleigh_M/0/1/0/all/0/1">Matthew R. Burleigh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Casewell_S/0/1/0/all/0/1">Sarah L. Casewell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Breytenbach_H/0/1/0/all/0/1">Hannes Breytenbach</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nielsen_L/0/1/0/all/0/1">Louise D. Nielsen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_G/0/1/0/all/0/1">Gareth Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_D/0/1/0/all/0/1">David R. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Battley_M/0/1/0/all/0/1">Matthew P. Battley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bayliss_D/0/1/0/all/0/1">Daniel Bayliss</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bouchy_F/0/1/0/all/0/1">Fran&#xe7;ois Bouchy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bryant_E/0/1/0/all/0/1">Edward M. Bryant</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Csizmadia_S/0/1/0/all/0/1">Szil&#xe1;rd Csizmadia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eigmuller_P/0/1/0/all/0/1">Phillip Eigm&#xfc;ller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gill_S/0/1/0/all/0/1">Samuel Gill</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gillen_E/0/1/0/all/0/1">Edward Gillen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grieves_N/0/1/0/all/0/1">Nolan Grieves</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gunther_M/0/1/0/all/0/1">Maximilian N. G&#xfc;nther</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Henderson_B/0/1/0/all/0/1">Beth A. Henderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hodgkin_S/0/1/0/all/0/1">Simon T. Hodgkin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jackman_J/0/1/0/all/0/1">James A. G. Jackman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jenkins_J/0/1/0/all/0/1">James S. Jenkins</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lendl_M/0/1/0/all/0/1">Monika Lendl</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McCormac_J/0/1/0/all/0/1">James McCormac</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moyano_M/0/1/0/all/0/1">Maximiliano Moyano</a>,Read More →

Strong constraints on Lorentz violation using new $gamma$-ray observations around PeV. (arXiv:2105.07927v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_L/0/1/0/all/0/1">Liang Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xiong_Z/0/1/0/all/0/1">Zheng Xiong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_C/0/1/0/all/0/1">Cong Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_S/0/1/0/all/0/1">SongZhan Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+He_H/0/1/0/all/0/1">HuiHai He</a> The tiny modification of dispersion relation induced by Lorentz violation (LV) is an essential issue in quantum gravity (QG) theories, which can be magnified into significant effects when dealing with astrophysical observations at high energy and long propagation distance. LV would lead to photon decay at high energies, therefore, observations of high-energy photons could constrain LV or even QG theories. The Large High Altitude Air Shower Observatory (LHAASO) is the most sensitive gamma-array instrument currently operatingRead More →

I3T: Intensity Interferometry Imaging Telescope. (arXiv:2105.07072v2 [astro-ph.IM] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Gori_P/0/1/0/all/0/1">Pierre-Marie Gori</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vakili_F/0/1/0/all/0/1">Farrokh Vakili</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rivet_J/0/1/0/all/0/1">Jean-Pierre Rivet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guerin_W/0/1/0/all/0/1">William Guerin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hugbart_M/0/1/0/all/0/1">Mathilde Hugbart</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiavassa_A/0/1/0/all/0/1">Andrea Chiavassa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vakili_A/0/1/0/all/0/1">Adrien Vakili</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kaiser_R/0/1/0/all/0/1">Robin Kaiser</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Labeyrie_G/0/1/0/all/0/1">Guillaume Labeyrie</a> We propose a new approach, based on the Hanbury Brown and Twiss intensity interferometry, to transform a Cherenkov telescope to its equivalent optical telescope. We show that, based on the use of photonics components borrowed from quantum-optical applications, we can recover spatial details of the observed source down to the diffraction limit of the Cherenkov telescope, set by its diameter at the mean wavelength of observation. For this, we proposeRead More →

Challenges for $Lambda$CDM: An update. (arXiv:2105.05208v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Perivolaropoulos_L/0/1/0/all/0/1">Leandros Perivolaropoulos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Skara_F/0/1/0/all/0/1">Foteini Skara</a> A number of challenges of the standard $Lambda$CDM model has been emerging during the past few years as the accuracy of cosmological observations improves. In this review we discuss in a unified manner many existing signals in cosmological and astrophysical data that appear to be in some tension ($2sigma$ or larger) with the standard $Lambda$CDM model as defined by the Planck18 parameter values. In addition to the major well studied $5sigma$ challenge of $Lambda$CDM (the Hubble $H_0$ crisis) and other well known tensions (the growth tension and the lensing amplitude $A_L$Read More →

Galaxy Properties at the Faint End of the HI Mass Function. (arXiv:2105.05100v3 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+McQuinn_K/0/1/0/all/0/1">Kristen B. W. McQuinn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Telidevara_A/0/1/0/all/0/1">Anjana K. Telidevara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fuson_J/0/1/0/all/0/1">Jackson Fuson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adams_E/0/1/0/all/0/1">Elizabeth A. K. Adams</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cannon_J/0/1/0/all/0/1">John M. Cannon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Skillman_E/0/1/0/all/0/1">Evan D. Skillman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dolphin_A/0/1/0/all/0/1">Andrew E. Dolphin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Haynes_M/0/1/0/all/0/1">Martha P. Haynes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rhode_K/0/1/0/all/0/1">Katherine L. Rhode</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salzer_J/0/1/0/all/0/1">John. J. Salzer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giovanelli_R/0/1/0/all/0/1">Riccardo Giovanelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gordon_A/0/1/0/all/0/1">Alex J. R. Gordon</a> The Survey of HI in Extremely Low-mass Dwarfs (SHIELD) includes a volumetrically complete sample of 82 gas-rich dwarfs with M_HI~<10^7.2 Msun selected from the ALFALFA survey. We are obtaining extensive follow-up observations of the SHIELD galaxies to study their gas, stellar, andRead More →

Dark photon limits: a cookbook. (arXiv:2105.04565v2 [hep-ph] UPDATED) <a href="http://arxiv.org/find/hep-ph/1/au:+Caputo_A/0/1/0/all/0/1">Andrea Caputo</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Millar_A/0/1/0/all/0/1">Alexander J. Millar</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+OHare_C/0/1/0/all/0/1">Ciaran A. J. O&#x27;Hare</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Vitagliano_E/0/1/0/all/0/1">Edoardo Vitagliano</a> The dark photon is a massive hypothetical particle that interacts with the Standard Model by kinetically mixing with the visible photon. For small values of the mixing parameter, dark photons can evade cosmological bounds to be a viable dark matter candidate. Due to the similarities with the electromagnetic signals generated by axions, several bounds on dark photon signals are simply reinterpretations of historical bounds set by axion haloscopes. However, the dark photon has a property that the axion does not: an intrinsicRead More →

The Drake Equation at 60: Reconsidered and Abandoned. (arXiv:2105.03984v2 [physics.pop-ph] UPDATED) <a href="http://arxiv.org/find/physics/1/au:+Gertz_J/0/1/0/all/0/1">John Gertz</a> Each of the individual factors of the Drake Equation is considered. Each in turn is either abandoned or redefined and finally reduced to a single new factor, fd, the fraction of technological life that is detectable by any means. However, neither the Drake Equation, nor its replacement, can actually solve for N. Only a vibrant SETI program and, ultimately, contact with an alien civilization might result in the determination of N. Each of the individual factors of the Drake Equation is considered. Each in turn is either abandoned or redefined andRead More →

Thermal evolution of Uranus and Neptune II — Deep thermal boundary layer. (arXiv:2105.01359v2 [astro-ph.EP] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Scheibe_L/0/1/0/all/0/1">Ludwig Scheibe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nettelmann_N/0/1/0/all/0/1">Nadine Nettelmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Redmer_R/0/1/0/all/0/1">Ronald Redmer</a> Thermal evolution models suggest that the luminosities of both Uranus and Neptune are inconsistent with the classical assumption of an adiabatic interior. Such models commonly predict Uranus to be brighter and, recently, Neptune to be fainter than observed. In this work, we investigate the influence of a thermally conductive boundary layer on the evolution of Uranus- and Neptune-like planets. This thermal boundary layer (TBL) is assumed to be located deep in the planet, and be caused by a steep compositional gradientRead More →

A deep $XMM-Newton$ observation of the X-Persei-like binary system CXOU J225355.1+624336. (arXiv:2104.09868v3 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Palombara_N/0/1/0/all/0/1">N. La Palombara</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Sidoli_L/0/1/0/all/0/1">L. Sidoli</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Esposito_P/0/1/0/all/0/1">P. Esposito</a> (1, 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Israel_G/0/1/0/all/0/1">G. L. Israel</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Castillo_G/0/1/0/all/0/1">G. A. Rodr&#xed;guez Castillo</a> (4) ((1) INAF – IASF Milano, (2) IUSS Pavia, (3) INAF – OA Roma, (4) INAF – IASF Palermo) We report on the follow-up $XMM-Newton$ observation of the persistent X-ray pulsar CXOU J225355.1+624336, discovered with the CATS@BAR project on archival $Chandra$ data. The source was detected at $f_{rm X}$(0.5-10 keV) = 3.4$times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$, a flux level which is fully consistent with the previous observationsRead More →

The Flare and Warp of the Young Stellar Disk traced with LAMOST DR5 OB-type stars. (arXiv:2102.00731v3 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Yu_Y/0/1/0/all/0/1">Yang Yu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_H/0/1/0/all/0/1">Hai-Feng Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cui_W/0/1/0/all/0/1">Wen-Yuan Cui</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_L/0/1/0/all/0/1">Lin-Lin Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_C/0/1/0/all/0/1">Chao Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_B/0/1/0/all/0/1">Bo Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tian_H/0/1/0/all/0/1">Hao Tian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huo_Z/0/1/0/all/0/1">Zhen-Yan Huo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ju_J/0/1/0/all/0/1">Jie Ju</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_Z/0/1/0/all/0/1">Zhi-Cun Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wen_F/0/1/0/all/0/1">Fang Wen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feng_S/0/1/0/all/0/1">Shuai Feng</a> We present analysis of the spatial density structure for the outer disk from 8$-$14 ,kpc with the LAMOST DR5 13534 OB-type stars. We observe similar flaring on north and south sides of the disk implying that the structure is symmetrical about the Galactic plane, for which the scale height is fromRead More →

TOI-1634 b: an Ultra-Short Period Keystone Planet Sitting Inside the M Dwarf Radius Valley. (arXiv:2103.12790v2 [astro-ph.EP] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Cloutier_R/0/1/0/all/0/1">R. Cloutier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charbonneau_D/0/1/0/all/0/1">D. Charbonneau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stassun_K/0/1/0/all/0/1">K.G. Stassun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Murgas_F/0/1/0/all/0/1">F. Murgas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mortier_A/0/1/0/all/0/1">A. Mortier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Massey_R/0/1/0/all/0/1">R. Massey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lissauer_J/0/1/0/all/0/1">J.J. Lissauer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Latham_D/0/1/0/all/0/1">D.W. Latham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Irwin_J/0/1/0/all/0/1">J. Irwin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Haywood_R/0/1/0/all/0/1">R.D. Haywood</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guerra_P/0/1/0/all/0/1">P. Guerra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Girardin_E/0/1/0/all/0/1">E. Girardin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giacalone_S/0/1/0/all/0/1">S.A. Giacalone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bosch_Cabot_P/0/1/0/all/0/1">P. Bosch-Cabot</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bieryla_A/0/1/0/all/0/1">A. Bieryla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Winn_J/0/1/0/all/0/1">J. Winn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Watson_C/0/1/0/all/0/1">C.A. Watson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vanderspek_R/0/1/0/all/0/1">R. Vanderspek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Udry_S/0/1/0/all/0/1">S. Udry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tamura_M/0/1/0/all/0/1">M. Tamura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sozzetti_A/0/1/0/all/0/1">A. Sozzetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shporer_A/0/1/0/all/0/1">A. Shporer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Segransan_D/0/1/0/all/0/1">D. S&#xe9;gransan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Seager_S/0/1/0/all/0/1">S. Seager</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Savel_A/0/1/0/all/0/1">A.B. Savel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sasselov_D/0/1/0/all/0/1">D. Sasselov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rose_M/0/1/0/all/0/1">M. Rose</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricker_G/0/1/0/all/0/1">G. Ricker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rice_K/0/1/0/all/0/1">K. Rice</a>, <aRead More →

Radiative Driving of the AGN Outflows in the Narrow-Line Seyfert 1 Galaxy NGC 4051. (arXiv:2103.12081v2 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Meena_B/0/1/0/all/0/1">Beena Meena</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Crenshaw_D/0/1/0/all/0/1">D. Michael Crenshaw</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schmitt_H/0/1/0/all/0/1">Henrique R. Schmitt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Revalski_M/0/1/0/all/0/1">Mitchell Revalski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fischer_T/0/1/0/all/0/1">Travis C. Fischer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Polack_G/0/1/0/all/0/1">Garrett E. Polack</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kraemer_S/0/1/0/all/0/1">Steven B. Kraemer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dashtamirova_D/0/1/0/all/0/1">Dzhuliya Dashtamirova</a> We explore the properties of ionized gas in the nuclear and circumnuclear environment of the narrow-line Seyfert 1 galaxy NGC 4051 using spectroscopic and imaging observations from the Hubble Space Telescope (HST) and Apache Point Observatory (APO)’s ARC 3.5m Telescope. We identify an unresolved moderate-density intermediate width component and a high-density broad component in the optical emission lines fromRead More →

Targeting Bright Metal-poor Stars in the Disk and Halo Systems of the Galaxy. (arXiv:2103.07621v3 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Limberg_G/0/1/0/all/0/1">Guilherme Limberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Santucci_R/0/1/0/all/0/1">Rafael M. Santucci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rossi_S/0/1/0/all/0/1">Silvia Rossi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shank_D/0/1/0/all/0/1">Derek Shank</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Placco_V/0/1/0/all/0/1">Vinicius M. Placco</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:+Schlaufman_K/0/1/0/all/0/1">Kevin C. Schlaufman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Casey_A/0/1/0/all/0/1">Andrew R. Casey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perottoni_H/0/1/0/all/0/1">H&#xe9;lio D. Perottoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_Y/0/1/0/all/0/1">Young Sun Lee</a> We present the results of spectroscopic follow-up for 1897 low-metallicity star candidates, selected from the Best & Brightest (B&B) Survey, carried out with the GMOS-N/S (Gemini North/South telescopes) and Goodman (SOAR Telescope) spectrographs. From these low-resolution ($R sim 2000$) spectra, we estimate stellar atmospheric parameters, as well as carbon and magnesium (representativeRead More →

A model independent approach to the study of $f(R)$ cosmologies with expansion histories close to $Lambda$CDM. (arXiv:2103.02274v3 [gr-qc] UPDATED) <a href="http://arxiv.org/find/gr-qc/1/au:+Chakraborty_S/0/1/0/all/0/1">Saikat Chakraborty</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+MacDevette_K/0/1/0/all/0/1">Kelly MacDevette</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Dunsby_P/0/1/0/all/0/1">Peter Dunsby</a> We propose a new framework for studying the cosmology of $f(R)$ gravity which completely avoids using the reconstruction programme. This allows us to easily obtain a qualitative feel of how much the $Lambda$CDM model differs from other $f(R)$ theories of gravity at the level of linear perturbation theory for theories that share the same background dynamics. This is achieved by using the standard model independent cosmographic parameters to develop a new dynamical system formulation of $f(R)$ gravityRead More →

A preliminary study about gravitational wave radiation and cosmic heat death. (arXiv:2102.12054v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_J/0/1/0/all/0/1">Jianming Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Qian_Q/0/1/0/all/0/1">Qiyue Qian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guo_Y/0/1/0/all/0/1">Yiqing Guo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_X/0/1/0/all/0/1">Xin Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_X/0/1/0/all/0/1">Xiao-Dong Li</a> We study the role of gravitational waves (GW) in the heat death of the universe. Due to the GW emission, in a very long period, dynamical systems in the universe suffer from persistent mechanical energy dissipation, evolving to a state of universal rest and death. With N-body simulations, we adopt a simple yet representative scheme to calculate the energy loss due to the GW emission. For current dark matter systems with mass $sim10^{12}-10^{15} M_odot$, we estimateRead More →

Connecting multi-lepton anomalies at the LHC and in Astrophysics and the prospects of MeerKAT/SKA. (arXiv:2102.10596v4 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Beck_G/0/1/0/all/0/1">Geoff Beck</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_M/0/1/0/all/0/1">Mukesh Kumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Malwa_E/0/1/0/all/0/1">Elias Malwa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mellado_B/0/1/0/all/0/1">Bruce Mellado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Temo_R/0/1/0/all/0/1">Ralekete Temo</a> Multi-lepton anomalies at the Large Hadron Collider are reasonably well described by a two Higgs doublet model with an additional singlet scalar. Here, we demonstrate that using this model we are also able to describe the excesses in gamma-ray flux from the galactic centre and the cosmic-ray spectra from AMS-02. This is achieved through Dark Matter (DM) annihilation via the singlet scalar. Of great interest is the flux of synchrotron emissions which resultsRead More →

Cosmological Magnetogenesis: The Biermann Battery during the Epoch of Reionization. (arXiv:2102.09535v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Attia_O/0/1/0/all/0/1">Omar Attia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Teyssier_R/0/1/0/all/0/1">Romain Teyssier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Katz_H/0/1/0/all/0/1">Harley Katz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kimm_T/0/1/0/all/0/1">Taysun Kimm</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martin_Alvarez_S/0/1/0/all/0/1">Sergio Martin-Alvarez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ocvirk_P/0/1/0/all/0/1">Pierre Ocvirk</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosdahl_J/0/1/0/all/0/1">Joakim Rosdahl</a> We investigate the effect of the Biermann battery during the Epoch of Reionization (EoR) using cosmological Adaptive Mesh Refinement simulations within the framework of the SPHINX project. We develop a novel numerical technique to solve for the Biermann battery term in the Constrained Transport method, preserving both the zero divergence of the magnetic field and the absence of Biermann battery for isothermal flows. The structure-preserving nature of our numerical method turnsRead More →

Calibration of the Advanced Spectral Leakage scheme for neutron star merger simulations, and extension to smoothed-particle hydrodynamics. (arXiv:2102.08882v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Gizzi_D/0/1/0/all/0/1">Davide Gizzi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lundman_C/0/1/0/all/0/1">Christoffer Lundman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+OConnor_E/0/1/0/all/0/1">Evan O&#x27;Connor</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosswog_S/0/1/0/all/0/1">Stephan Rosswog</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perego_A/0/1/0/all/0/1">Albino Perego</a> We calibrate a neutrino transport approximation, called Advanced Spectral Leakage (ASL), with the purpose of modeling neutrino-driven winds in neutron star mergers. Based on a number of snapshots we gauge the ASL parameters by comparing against both the two-moment (M1) scheme implemented in the FLASH code and the Monte Carlo neutrino code Sedonu. The ASL scheme contains three parameters, the least robust of which results to be a blocking parameterRead More →