RAS_WEB (Page 3,997)

Euclid Preparation IV. Impact of undetected galaxies on weak lensing shear measurements. (arXiv:1902.00044v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Collaboration_Euclid/0/1/0/all/0/1">Euclid Collaboration</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martinet_N/0/1/0/all/0/1">N. Martinet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schrabback_T/0/1/0/all/0/1">T. Schrabback</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hoekstra_H/0/1/0/all/0/1">H. Hoekstra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tewes_M/0/1/0/all/0/1">M. Tewes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Herbonnet_R/0/1/0/all/0/1">R. Herbonnet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schneider_P/0/1/0/all/0/1">P. Schneider</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernandez_Martin_B/0/1/0/all/0/1">B. Hernandez-Martin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Taylor_A/0/1/0/all/0/1">A.N. Taylor</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brinchmann_J/0/1/0/all/0/1">J. Brinchmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carvalho_C/0/1/0/all/0/1">C.S. Carvalho</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Castellano_M/0/1/0/all/0/1">M. Castellano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Congedo_G/0/1/0/all/0/1">G. Congedo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gillis_B/0/1/0/all/0/1">B.R. Gillis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jullo_E/0/1/0/all/0/1">E. Jullo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kummel_M/0/1/0/all/0/1">M. K&#xfc;mmel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ligori_S/0/1/0/all/0/1">S. Ligori</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lilje_P/0/1/0/all/0/1">P.B. Lilje</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Padilla_C/0/1/0/all/0/1">C. Padilla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paris_D/0/1/0/all/0/1">D. Paris</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Peacock_J/0/1/0/all/0/1">J.A. Peacock</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pilo_S/0/1/0/all/0/1">S. Pilo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pujol_A/0/1/0/all/0/1">A. Pujol</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Scott_D/0/1/0/all/0/1">D. Scott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toledo_Moreo_R/0/1/0/all/0/1">R. Toledo-Moreo</a> In modern weak lensing surveys, shape measurement algorithms are calibrated using simulations in order to correctRead More →

Topography of (exo)planets. (arXiv:1902.00047v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Landais_F/0/1/0/all/0/1">Fran&#xe7;ois Landais</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schmidt_F/0/1/0/all/0/1">Frederic Schmidt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lovejoy_S/0/1/0/all/0/1">Shaun Lovejoy</a> Current technology is not able to map the topography of rocky exoplanets, simply because the objects are too faint and far away to resolve them. Nevertheless, indirect effect of topography should be soon observable thanks to photometry techniques, and the possibility of detecting specular reflections. In addition, topography may have a strong effect on Earth-like exoplanet climates because oceans and mountains affect the distribution of clouds citep{Houze2012}. Also topography is critical for evaluating surface habitability citep{Dohm2015}. We propose here a general statistical theory to describe and generate realistic synthetic topographies ofRead More →

Inaccuracy of Spatial Derivatives in Simulations of Supersonic Turbulence. (arXiv:1902.00079v1 [physics.flu-dyn]) <a href="http://arxiv.org/find/physics/1/au:+Pan_L/0/1/0/all/0/1">Liubin Pan</a>, <a href="http://arxiv.org/find/physics/1/au:+Padoan_P/0/1/0/all/0/1">Paolo Padoan</a>, <a href="http://arxiv.org/find/physics/1/au:+Nordlund_%7B/0/1/0/all/0/1">&#xc5;ke Nordlund</a> We examine the accuracy of spatial derivatives computed from numerical simulations of supersonic turbulence. Two sets of simulations, carried out using a finite-volume code that evolves the hydrodynamic equations with an approximate Riemann solver and a finite-difference code that solves the Navier-Stokes equations, are tested against a number of criteria based on the continuity equation, including exact results at statistically steady state. We find that the spatial derivatives in the Navier-Stokes runs are accurate and satisfy all the criteria. In particular, they satisfy our exactRead More →

Star Cluster Catalogs for the LEGUS Dwarf Galaxies. (arXiv:1902.00082v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Cook_D/0/1/0/all/0/1">D.O. Cook</a> (1 and 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_J/0/1/0/all/0/1">J.C. Lee</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Adamo_A/0/1/0/all/0/1">A. Adamo</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Kim_H/0/1/0/all/0/1">H. Kim</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Chandar_R/0/1/0/all/0/1">R. Chandar</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Whitmore_B/0/1/0/all/0/1">B.C. Whitmore</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Mok_A/0/1/0/all/0/1">A. Mok</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Ryon_J/0/1/0/all/0/1">J.E. Ryon</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Dale_D/0/1/0/all/0/1">D.A. Dale</a> (7), <a href="http://arxiv.org/find/astro-ph/1/au:+Calzetti_D/0/1/0/all/0/1">D. Calzetti</a> (8), <a href="http://arxiv.org/find/astro-ph/1/au:+Andrews_J/0/1/0/all/0/1">J.E. Andrews</a> (9), <a href="http://arxiv.org/find/astro-ph/1/au:+Aloisi_A/0/1/0/all/0/1">A. Aloisi</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Ashworth_G/0/1/0/all/0/1">G. Ashworth</a> (10), <a href="http://arxiv.org/find/astro-ph/1/au:+Bright_S/0/1/0/all/0/1">S.N. Bright</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_T/0/1/0/all/0/1">T.M. Brown</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Christian_C/0/1/0/all/0/1">C. Christian</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Cignoni_M/0/1/0/all/0/1">M. Cignoni</a> (11), <a href="http://arxiv.org/find/astro-ph/1/au:+Clayton_G/0/1/0/all/0/1">G.C. Clayton</a> (12), <a href="http://arxiv.org/find/astro-ph/1/au:+Silva_R/0/1/0/all/0/1">R. da Silva</a> (13), <a href="http://arxiv.org/find/astro-ph/1/au:+Mink_S/0/1/0/all/0/1">S.E. de Mink</a> (14), <a href="http://arxiv.org/find/astro-ph/1/au:+Dobbs_C/0/1/0/all/0/1">C.L. Dobbs</a> (15), <a href="http://arxiv.org/find/astro-ph/1/au:+Elmegreen_B/0/1/0/all/0/1">B.G. Elmegreen</a> (16), <a href="http://arxiv.org/find/astro-ph/1/au:+Elmegreen_D/0/1/0/all/0/1">D.M. Elmegreen</a>Read More →

Cloud Atlas: High-Contrast Time-Resolved Observations of Planetary-Mass Companions. (arXiv:1902.00085v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zhou_Y/0/1/0/all/0/1">Yifan Zhou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Apai_D/0/1/0/all/0/1">D&#xe1;niel Apai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lew_B/0/1/0/all/0/1">Ben W. P. Lew</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schneider_G/0/1/0/all/0/1">Glenn Schneider</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Manjavacas_E/0/1/0/all/0/1">Elena Manjavacas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bedin_L/0/1/0/all/0/1">Luigi R. Bedin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cowan_N/0/1/0/all/0/1">Nicolas B. Cowan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marley_M/0/1/0/all/0/1">Mark S. Marley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Radigan_J/0/1/0/all/0/1">Jacqueline Radigan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+karalidi_T/0/1/0/all/0/1">Theodora karalidi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lowrance_P/0/1/0/all/0/1">Patrick J. Lowrance</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miels_Paez_P/0/1/0/all/0/1">Paulo A. Miels-P&#xe1;ez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Metchev_S/0/1/0/all/0/1">Stanimir Metchev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burgasser_A/0/1/0/all/0/1">Adam J. Burgasser</a> Directly-imaged planetary-mass companions offer unique opportunities in atmospheric studies of exoplanets. They share characteristics of both brown dwarfs and transiting exoplanets, therefore, are critical for connecting atmospheric characterizations for these objects. Rotational phase mapping is a powerful technique to constrain the condensate cloud properties inRead More →

Modelling of Mg II lines in solar prominences. (arXiv:1902.00086v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Levens_P/0/1/0/all/0/1">Peter James Levens</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Labrosse_N/0/1/0/all/0/1">Nicolas Labrosse</a> Observations of the Mg II h and k lines in solar prominences with IRIS reveal a wide range of line shapes from simple non-reversed profiles to typical double-peaked reversed profiles with many other complex line shapes possible. The physical conditions responsible for this variety are not well understood. Our aim is to understand how physical conditions inside a prominence slab influence shapes and properties of emergent Mg II line profiles. We compute the spectrum of Mg II lines using a one-dimensional non-LTE radiative transfer code for two largeRead More →

Production and detection of an axion dark matter echo. (arXiv:1902.00114v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Arza_A/0/1/0/all/0/1">Ariel Arza</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Sikivie_P/0/1/0/all/0/1">Pierre Sikivie</a> Electromagnetic radiation with angular frequency equal to half the axion mass stimulates the decay of cold dark matter axions and produces an echo, i.e. faint electromagnetic radiation traveling in the opposite direction. We propose to search for axion dark matter by sending out to space a powerful beam of microwave radiation and listening for its echo. We find that this is a promising approach to axion detection in the $2 times 10^{-7}$ to $3 times 10^{-4}$ eV mass range. Electromagnetic radiation with angular frequency equal to half theRead More →

Neutron Star Interior Composition Exporer X-ray Timing of the Radio and Gamma-ray Quiet Pulsars PSR J1412+7922 AND PSR J1849-0001. (arXiv:1902.00144v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bogdanov_S/0/1/0/all/0/1">Slavko Bogdanov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ho_W/0/1/0/all/0/1">Wynn C. G. Ho</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Enoto_T/0/1/0/all/0/1">Teruaki Enoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guillot_S/0/1/0/all/0/1">Sebastien Guillot</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harding_A/0/1/0/all/0/1">Alice K. Harding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jaisawal_G/0/1/0/all/0/1">Gaurava K. Jaisawal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Malacaria_C/0/1/0/all/0/1">Christian Malacaria</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Manthripragada_S/0/1/0/all/0/1">Sridhar S. Manthripragada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arzoumanian_Z/0/1/0/all/0/1">Zaven Arzoumanian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gendreau_K/0/1/0/all/0/1">Keith C. Gendreau</a> We present new timing and spectral analyses of PSR J1412+7922 (Calvera) and PSR J1849-0001, which are only seen as pulsars in X-rays, based on observations conducted with the Neutron Star Interior Composition Explorer (NICER). We obtain updated and substantially improved pulse ephemerides compared to previous X-ray studies, asRead More →

Quark-Hadron Crossover with Vortices. (arXiv:1902.00156v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Chatterjee_C/0/1/0/all/0/1">Chandrasekhar Chatterjee</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Nitta%2E_M/0/1/0/all/0/1">Muneto Nitta.</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Yasui_S/0/1/0/all/0/1">Shigehiro Yasui</a> The quark-hadron crossover conjecture was proposed as a continuity between hadronic matter and quark matter with no phase transition. It is based on matching of symmetry and excitations in both the phases. It connects hyperon matter and color-flavor locked (CFL) phase of color superconductivity in the limit of light strange quark mass. We study generalization of this conjecture in the presence of topological vortices. We propose a picture where hadronic superfluid vortices in hyperon matter could be connected to non-Abelian vortices (color magnetic flux tubes) in the CFL phase duringRead More →

The Synthetic ALMA Multiband Analysis of the Dust Properties of the TW Hya Protoplanetary Disk. (arXiv:1902.00168v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kim_S/0/1/0/all/0/1">Seongjoong Kim</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nomura_H/0/1/0/all/0/1">Hideko Nomura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tsukagoshi_T/0/1/0/all/0/1">Takashi Tsukagoshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kawabe_R/0/1/0/all/0/1">Ryohei Kawabe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Muto_T/0/1/0/all/0/1">Takayuki Muto</a> Analyzing multiband observations of dust continuum emission is one of the useful tools to constrain dust properties which help us to understand the physical properties of the disks. We perform the synthetic ALMA multiband analysis to find the best ALMA band set for constraining the dust properties of the TW Hya protoplanetary disk. We find that the Band [10,6,3] set is the best set among the possible combinations of ALMA Band [3,4,5,6,7,8,9,10]. WeRead More →

Evolution of the Sun’s Polar-fields and the Poleward Transport of Remnant Magnetic Flux. (arXiv:1902.00199v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mordvinov_A/0/1/0/all/0/1">A. V. Mordvinov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kitchatinov_L/0/1/0/all/0/1">L. L. Kitchatinov</a> Synoptic magnetograms and relevant proxy data were analyzed to study the evolution of the Sun’s polar magnetic fields. Time-latitude analysis of large-scale magnetic fields demonstrates cyclic changes in their zonal structure and the polar-field buildup. The time-latitude distributions of the emergent and remnant magnetic flux enable us to examine individual features of recent cycles. The poleward transport of predominantly following polarities contributed much of the polar flux and led to polar-field reversals. Multiple reversals of dominant polarities at the Sun’s poles wereRead More →

Determining normal mode features from numerical simulations using CEOF analysis: I. Test case. (arXiv:1902.00211v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rial_S/0/1/0/all/0/1">S. Rial</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arregui_I/0/1/0/all/0/1">I. Arregui</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oliver_R/0/1/0/all/0/1">R. Oliver</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Terradas_J/0/1/0/all/0/1">J. Terradas</a> We present a method to determine approximations to a system’s normal mode eigenfrequency and eigenfunctions from time-dependent numerical simulations. The method proceeds iteratively and each step consists of (i) a time-dependent numerical simulation followed by (ii) the Complex Empirical Orthogonal Function (CEOF) analysis of the simulation results. The CEOF analysis provides an approximation to the normal mode eigenfunctions that can be used to set up the initial conditions for the numerical simulation of the following iteration, in whichRead More →

Unbiased Cosmic Opacity Constraints from Standard Sirens and Candles. (arXiv:1902.00223v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Wei_J/0/1/0/all/0/1">Jun-Jie Wei</a> The observation of Type Ia supernovae (SNe Ia) plays an essential role in probing the expansion history of the universe. But the possible presence of cosmic opacity can degrade the quality of SNe Ia. The gravitational-wave (GW) standard sirens, produced by the coalescence of double neutron stars and black hole–neutron star binaries, provide an independent way to measure the distances of GW sources, which are not affected by cosmic opacity. In this paper, we first propose that combining the GW observations of third-generation GW detectors with SN Ia data in similarRead More →

Evidence for a merger induced shock wave in ZwCl,0008.8+5215 with {it Chandra} and {it Suzaku}. (arXiv:1902.00235v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Gennaro_G/0/1/0/all/0/1">G. Di Gennaro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weeren_R/0/1/0/all/0/1">R.J. van Weeren</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andrade_Santos_F/0/1/0/all/0/1">F. Andrade-Santos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Akamatsu_H/0/1/0/all/0/1">H. Akamatsu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Randall_S/0/1/0/all/0/1">S.W. Randall</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Forman_W/0/1/0/all/0/1">W. Forman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kraft_R/0/1/0/all/0/1">R.P. Kraft</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brunetti_G/0/1/0/all/0/1">G. Brunetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dawson_W/0/1/0/all/0/1">W.A. Dawson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Golovich_N/0/1/0/all/0/1">N. Golovich</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jones_C/0/1/0/all/0/1">C. Jones</a> We present the results from new deep {it Chandra} ($sim410$~ks) and {it Suzaku} ($sim180$ ks) observations of the merging galaxy cluster ZwCl,0008.8+5215 ($z=0.104$). Previous radio observations revealed the presence of a double radio relic located diametrically west and east of the cluster center. Using our new {it Chandra} data, we find evidence forRead More →

A Fokker-Planck Framework for Studying the Diffusion of Radio Burst Waves in the Solar Corona. (arXiv:1902.00239v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bian_N/0/1/0/all/0/1">N. H. Bian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Emslie_A/0/1/0/all/0/1">A. G. Emslie</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kontar_E/0/1/0/all/0/1">E. P. Kontar</a> Electromagnetic wave scattering off density inhomogeneities in the solar corona is an important process which determines both the apparent source size and the time profile of radio bursts observed at 1 AU. Here we model the scattering process using a Fokker-Planck equation and apply this formalism to several regimes of interest. In the first regime the density fluctuations are considered quasi-static and diffusion in wavevector space is dominated by angular diffusion on the surface of aRead More →

Shocks and non-thermal particles in clusters of galaxies. (arXiv:1902.00240v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bykov_A/0/1/0/all/0/1">A.M.Bykov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vazza_F/0/1/0/all/0/1">F.Vazza</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kropotina_J/0/1/0/all/0/1">J.A.Kropotina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Levenfish_K/0/1/0/all/0/1">K.P.Levenfish</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paerels_F/0/1/0/all/0/1">F.B.S.Paerels</a> Galaxy clusters grow by gas accretion, mostly from mergers of substructures, which release powerful shock waves into cosmic plasmas and convert a fraction of kinetic energy into thermal energy, amplification of magnetic fields and into the acceleration of energetic particles. The modeling of the radio signature of cosmic shocks, combined with the lack of detected gamma-rays from cosmic ray (CR) protons, poses challenges to our understanding of how cosmic rays get accelerated and stored in the intracluster medium. Here we review the injection of CRsRead More →