RAS_WEB (Page 2,339)

Spinning Black Holes Fall in Love. (arXiv:2007.00214v2 [gr-qc] UPDATED) <a href="http://arxiv.org/find/gr-qc/1/au:+Tiec_A/0/1/0/all/0/1">Alexandre Le Tiec</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Casals_M/0/1/0/all/0/1">Marc Casals</a> The open question of whether a black hole can become tidally deformed by an external gravitational field has profound implications for fundamental physics, astrophysics and gravitational-wave astronomy. Love tensors characterize the tidal deformability of compact objects such as astrophysical (Kerr) black holes under an external static tidal field. We prove that all Love tensors vanish identically for a Kerr black hole in the nonspinning limit or for an axisymmetric tidal perturbation. In contrast to this result, we show that Love tensors are generically nonzero for a spinning black hole.Read More →

Time Delay Lens Modelling Challenge. (arXiv:2006.08619v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Ding_X/0/1/0/all/0/1">X. Ding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Treu_T/0/1/0/all/0/1">T. Treu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Birrer_S/0/1/0/all/0/1">S. Birrer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_G/0/1/0/all/0/1">G. C.-F. Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Coles_J/0/1/0/all/0/1">J. Coles</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Denzel_P/0/1/0/all/0/1">P. Denzel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Galan_M/0/1/0/all/0/1">M. Frigo A. Galan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marshall_P/0/1/0/all/0/1">P. J. Marshall</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Millon_M/0/1/0/all/0/1">M. Millon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+More_A/0/1/0/all/0/1">A. More</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shajib_A/0/1/0/all/0/1">A. J. Shajib</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sluse_D/0/1/0/all/0/1">D. Sluse</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tak_H/0/1/0/all/0/1">H. Tak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xu_D/0/1/0/all/0/1">D. Xu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Auger_M/0/1/0/all/0/1">M. W. Auger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bonvin_V/0/1/0/all/0/1">V. Bonvin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chand_H/0/1/0/all/0/1">H. Chand</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Courbin_F/0/1/0/all/0/1">F. Courbin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Despali_G/0/1/0/all/0/1">G. Despali</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fassnacht_C/0/1/0/all/0/1">C. D. Fassnacht</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gilman_D/0/1/0/all/0/1">D. Gilman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hilbert_S/0/1/0/all/0/1">S. Hilbert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_S/0/1/0/all/0/1">S. R. Kumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lin_Y/0/1/0/all/0/1">Y.-Y. Lin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Park_J/0/1/0/all/0/1">J. W. Park</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Saha_P/0/1/0/all/0/1">P. Saha</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vegetti_S/0/1/0/all/0/1">S. Vegetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vyvere_L/0/1/0/all/0/1">L. Van de Vyvere</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Williams_L/0/1/0/all/0/1">L.Read More →

The THESEUS space mission: updated design, profile and expected performances. (arXiv:2102.08702v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Amati_L/0/1/0/all/0/1">Lorenzo Amati</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+OBrien_P/0/1/0/all/0/1">Paul T. O&#x27;Brien</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gotz_D/0/1/0/all/0/1">Diego G&#xf6;tz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bozzo_E/0/1/0/all/0/1">Enrico Bozzo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Santangelo_A/0/1/0/all/0/1">Andrea Santangelo</a> (on behalf of the THESEUS Consortium) THESEUS is a space mission concept, currently under Phase A study by ESA as candidate M5 mission, aiming at exploiting Gamma-Ray Bursts for investigating the early Universe and at providing a substantial advancement of multi-messenger and time-domain astrophysics. In addition to fully exploiting high-redshift GRBs for cosmology (pop-III stars, cosmic re-ionization, SFR and metallicity evolution up to the “cosmic dawn”), THESEUS will allow the identification and study of the electromagnetic counterpartsRead More →

The soft X-ray imager on THESEUS: the transient high energy survey and early universe surveyor. (arXiv:2102.08700v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+OBrien_P/0/1/0/all/0/1">Paul O&#x27;Brien</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hutchinson_I/0/1/0/all/0/1">Ian Hutchinson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lerman_H/0/1/0/all/0/1">Hannah Natasha Lerman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feldman_C/0/1/0/all/0/1">Charlotte H. Feldman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McHugh_M/0/1/0/all/0/1">Melissa McHugh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lodge_A/0/1/0/all/0/1">Alexander Lodge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Willingale_R/0/1/0/all/0/1">Richard Willingale</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beardmore_A/0/1/0/all/0/1">Andy Beardmore</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Speight_R/0/1/0/all/0/1">Roisin Speight</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Drumm_P/0/1/0/all/0/1">Paul Drumm</a> We are entering a new era for high energy astrophysics with the use of new technology to increase our ability to both survey and monitor the sky. The Soft X-ray Imager (SXI) instrument on the THESEUS mission will revolutionize transient astronomy by using wide-field focusing optics to increase the sensitivity to fast transients by several ordersRead More →

A Comparison of Circumgalactic MgII Absorption between the TNG50 Simulation and the MEGAFLOW Survey. (arXiv:2102.08383v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+DeFelippis_D/0/1/0/all/0/1">Daniel DeFelippis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bouche_N/0/1/0/all/0/1">Nicolas F. Bouch&#xe9;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Genel_S/0/1/0/all/0/1">Shy Genel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bryan_G/0/1/0/all/0/1">Greg L. Bryan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nelson_D/0/1/0/all/0/1">Dylan Nelson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marinacci_F/0/1/0/all/0/1">Federico Marinacci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernquist_L/0/1/0/all/0/1">Lars Hernquist</a> The circumgalactic medium (CGM) contains information on gas flows around galaxies, such as accretion and supernova-driven winds, which are difficult to constrain from observations alone. Here, we use the high-resolution TNG50 cosmological magneto-hydrodynamical simulation to study the properties and kinematics of the CGM around star-forming galaxies in $10^{11.5}-10^{12};M_{odot}$ halos at $zsimeq1$ using mock MgII absorption lines, which we generate by post-processing halos to account for photoionizationRead More →

Smoothed Particle Radiation Hydrodynamics: Two-Moment method with Local Eddington Tensor Closure. (arXiv:2102.08404v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chan_T/0/1/0/all/0/1">T. K. Chan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Theuns_T/0/1/0/all/0/1">Tom Theuns</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bower_R/0/1/0/all/0/1">Richard Bower</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Frenk_C/0/1/0/all/0/1">Carlos Frenk</a> We present a new radiative transfer method (SPH-M1RT) that is coupled dynamically with smoothed particle hydrodynamics (SPH). We implement it in the (tasked-based parallel) SWIFT galaxy simulation code but it can be straightforwardly implemented to other SPH codes. Our moment-based method simultaneously solves the radiation energy and flux equations in SPH, making it adaptive in space and time. We modify the M1 closure relation to stabilize radiation fronts in the optically thin limit which performs well even in theRead More →

Constraints on power law cosmology from cosmic chronometer, standard ruler, and standard candle data. (arXiv:2102.08457v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ryan_J/0/1/0/all/0/1">Joseph Ryan</a> In this paper I compare the quality of the fit of a simple power law model of cosmic expansion to the standard $Lambda$CDM model. I analyze a data set consisting of cosmic chronometer, standard ruler, and standard candle measurements, finding that the $Lambda$CDM model provides a better fit to most combinations of these data than does the power law model In this paper I compare the quality of the fit of a simple power law model of cosmic expansion to the standard $Lambda$CDM model. I analyzeRead More →

Possibility of measurement of cosmic ray electron spectrum up to 100 TeV with two-layer water Cherenkov detector array. (arXiv:2102.08456v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Neronov_A/0/1/0/all/0/1">A.Neronov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Semikoz_D/0/1/0/all/0/1">D.Semikoz</a> Measurements of cosmic ray electron+positron spectrum above 10 TeV with ground-based experiments is challenging because of the difficulty of rejection of hadronic extensive air shower background. We study the efficiency of rejection of the hadronic background with water Cherenkov detector array supplemented by muon detection layer. We show that addition of a continuous muon detection layer to the experimental setup allows to achieve a ~ 1e-5 rejection factor for hadronic background at 10 TeV and enables measurement of electron spectrum inRead More →

Mesospheric nitric oxide model from SCIAMACHY data. (arXiv:2102.08455v1 [physics.ao-ph]) <a href="http://arxiv.org/find/physics/1/au:+Bender_S/0/1/0/all/0/1">Stefan Bender</a>, <a href="http://arxiv.org/find/physics/1/au:+Sinnhuber_M/0/1/0/all/0/1">Miriam Sinnhuber</a>, <a href="http://arxiv.org/find/physics/1/au:+Espy_P/0/1/0/all/0/1">Patrick J. Espy</a>, <a href="http://arxiv.org/find/physics/1/au:+Burrows_J/0/1/0/all/0/1">John P. Burrows</a> We present an empirical model for nitric oxide NO in the mesosphere ($approx$60–90 km) derived from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartoghraphY) limb scan data. This work complements and extends the NOEM (Nitric Oxide Empirical Model; Marsh et al., 2004) and SANOMA (SMR Acquired Nitric Oxide Model Atmosphere; Kiviranta et al., 2018) empirical models in the lower thermosphere. The regression ansatz builds on the heritage of studies by Hendrickx et al. (2017) and the superposed epoch analysis by Sinnhuber etRead More →

Successful Higgs inflation from combined nonminimal and derivative couplings. (arXiv:2102.08450v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Karydas_S/0/1/0/all/0/1">Stelios Karydas</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Papantonopoulos_E/0/1/0/all/0/1">Eleftherios Papantonopoulos</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Saridakis_E/0/1/0/all/0/1">Emmanuel N. Saridakis</a> We propose an inflationary scenario based on the concurrent presence of non-minimal coupling (NMC) and generalized non-minimal derivative coupling (GNMDC), in the context of Higgs inflation. The combined construction maintains the advantages of the individual scenarios without sharing their disadvantages. In particular, a long inflationary phase can be easily achieved due to the gravitational friction effect owed to the GNMDC, without leading to trans-Planckian values and unitarity violation. Additionally, the tensor-to-scalar ratio remains to low values due to the NMC contribution. Finally, the instabilitiesRead More →

On dark stars, Planck cores and the nature of dark matter. (arXiv:2102.07769v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Nikitin_I/0/1/0/all/0/1">Igor Nikitin</a> Dark stars are compact massive objects, described by Einstein gravitational field equations with matter. The type we consider possesses no event horizon, instead, there is a deep gravitational well with a very strong redshift factor. Observationally, dark stars can be identified with black holes. Inside dark stars, Planck density of matter is reached, Planck cores are formed, where the equations are modified by quantum gravity. In the paper, several models of dark stars with Planck cores are considered, resulting in the following hypothesis on the composition of dark matter.Read More →

On the dynamical interaction between overshooting convection and an underlying dipole magnetic field — I. The non-dynamo regime. (arXiv:2008.01857v2 [astro-ph.SR] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Korre_L/0/1/0/all/0/1">Lydia Korre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brummell_N/0/1/0/all/0/1">Nicholas H. Brummell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garaud_P/0/1/0/all/0/1">Pascale Garaud</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guervilly_C/0/1/0/all/0/1">Celine Guervilly</a> Motivated by the dynamics in the deep interiors of many stars, we study the interaction between overshooting convection and the large-scale poloidal fields residing in radiative zones. We have run a suite of 3D Boussinesq numerical calculations in a spherical shell that consists of a convection zone with an underlying stable region that initially compactly contains a dipole field. By varying the strength of the convective driving, we find that, inRead More →

Cosmic ray positrons from compact binary millisecond pulsars. (arXiv:2010.02844v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Linares_M/0/1/0/all/0/1">Manuel Linares</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kachelriess_M/0/1/0/all/0/1">Michael Kachelriess</a> A new population of neutron stars has emerged during the last decade: compact binary millisecond pulsars (CBMSPs). Because these pulsars and their companion stars are in tight orbits with typical separations of $10^{11}$ cm, their winds interact strongly forming an intrabinary shock. Electron-positron pairs reaccelerated at the shock can reach energies of about 10 TeV, which makes this new population a potential source of GeV-TeV cosmic ray positrons. We present an analytical model for the fluxes and spectra of positrons from intrabinary shocks of CBMSPs. We find thatRead More →

Small-Scale Dynamo in Supernova-Driven Interstellar Turbulence. (arXiv:2010.01833v4 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Gent_F/0/1/0/all/0/1">Frederick A. Gent</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Low_M/0/1/0/all/0/1">Mordecai-Mark Mac Low</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kapyla_M/0/1/0/all/0/1">Maarit J. Kapyla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Singh_N/0/1/0/all/0/1">Nishant K. Singh</a> Magnetic fields grow quickly even at early cosmological times, suggesting the action of a small-scale dynamo (SSD) in the interstellar medium of galaxies. Many studies have focused on idealized turbulent driving of the SSD. Here we simulate more realistic supernova-driven turbulence to determine whether it can drive an SSD. Magnetic field growth occurring in our models appears inconsistent with simple tangling of magnetic fields, but consistent with SSD action, reproducing and confirming models by Balsara et al. (2004) that didRead More →

A Possible kilonova powered by magnetic wind from a newborn black hole. (arXiv:2010.01338v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Ma_S/0/1/0/all/0/1">Shuai-Bing Ma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xie_W/0/1/0/all/0/1">Wei Xie</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liao_B/0/1/0/all/0/1">Bin Liao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_B/0/1/0/all/0/1">Bin-Bin Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_H/0/1/0/all/0/1">Hou-Jun L&#xfc;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_Y/0/1/0/all/0/1">Yu Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lei_W/0/1/0/all/0/1">Wei-Hua Lei</a> The merger of binary neutron stars (NS-NS) as the progenitor of short Gamma-ray bursts (GRBs) has been confirmed by the discovery of the association of the gravitational wave (GW) event GW170817 with GRB 170817A. However, the merger product of binary NS remains an open question. An X-ray plateau followed by a steep decay (“internal plateau”) has been found in some short GRBs, implying that a supra-massive magnetar operates asRead More →

Bayesian inference of dense matter EOS encapsulating a first-order hadron-quark phase transition from observables of canonical neutron stars. (arXiv:2009.13653v2 [nucl-th] UPDATED) <a href="http://arxiv.org/find/nucl-th/1/au:+Xie_W/0/1/0/all/0/1">Wen-Jie Xie</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Li_B/0/1/0/all/0/1">Bao-An Li</a> [Purpose:] We infer the posterior probability distribution functions (PDFs) and correlations of nine parameters characterizing the EOS of dense neutron-rich matter encapsulating a first-order hadron-quark phase transition from the radius data of canonical NSs reported by LIGO/VIRGO, NICER and Chandra Collaborations. We also infer the quark matter (QM) mass fraction and its radius in a 1.4 M$_{odot}$ NS and predict their values in more massive NSs. [Method:] Meta-modelings are used to generate both hadronic and QM EOSs inRead More →

Improved reconstruction of a stochastic gravitational wave background with LISA. (arXiv:2009.11845v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Flauger_R/0/1/0/all/0/1">Raphael Flauger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Karnesis_N/0/1/0/all/0/1">Nikolaos Karnesis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nardini_G/0/1/0/all/0/1">Germano Nardini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pieroni_M/0/1/0/all/0/1">Mauro Pieroni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricciardone_A/0/1/0/all/0/1">Angelo Ricciardone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Torrado_J/0/1/0/all/0/1">Jes&#xfa;s Torrado</a> We present a data analysis methodology for a model-independent reconstruction of the spectral shape of a stochastic gravitational wave background with LISA. We improve a previously proposed reconstruction algorithm that relied on a single Time-Delay-Interferometry (TDI) channel by including a complete set of TDI channels. As in the earlier work, we assume an idealized equilateral configuration. We test the improved algorithm with a number of case studies, including reconstruction in the presence of twoRead More →

On the Speed of Sound in Hyperonic Stars. (arXiv:2009.10908v2 [nucl-th] UPDATED) <a href="http://arxiv.org/find/nucl-th/1/au:+Motta_T/0/1/0/all/0/1">T. F. Motta</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Guichon_P/0/1/0/all/0/1">P. A. M. Guichon</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Thomas_A/0/1/0/all/0/1">A. W. Thomas</a> We build upon the remarkable, model independent constraints on the equation of state of dense baryonic matter established recently by Annala et al. [1]. Using the quark-meson coupling model, an approach to nuclear structure based upon the self-consistent adjustment of hadron structure to the local meson fields, we show that, once hyperons are allowed to appear in dense matter in b{eta}-equilibrium, the equation of state is consistent with those constraints. As a result, while one cannot rule out the occurence ofRead More →

Model Light Curves for Type Ib and Ic Supernovae. (arXiv:2009.06868v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Woosley_S/0/1/0/all/0/1">Stan Woosley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sukhbold_T/0/1/0/all/0/1">Tuguldur Sukhbold</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kasen_D/0/1/0/all/0/1">Daniel Kasen</a> Using the Monte Carlo code, SEDONA, multiband photometry and spectra are calculated for supernovae derived from stripped helium stars with presupernova masses from 2.2 to 10.0 $M_odot$. The models are representative of evolution in close binaries and have previously been exploded using a parametrized one-dimensional model for neutrino-transport. A subset, those with presupernova masses in the range 2.2 – 5.6 $M_odot$, have many properties in common with observed Type Ib and Ic supernovae, including a median ejected mass near 2 $M_odot$, explosion energies nearRead More →