RAS_WEB (Page 4,428)

The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project. (arXiv:1904.04923v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Porth_O/0/1/0/all/0/1">Oliver Porth</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chatterjee_K/0/1/0/all/0/1">Koushik Chatterjee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Narayan_R/0/1/0/all/0/1">Ramesh Narayan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gammie_C/0/1/0/all/0/1">Charles F. Gammie</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mizuno_Y/0/1/0/all/0/1">Yosuke Mizuno</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anninos_P/0/1/0/all/0/1">Peter Anninos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baker_J/0/1/0/all/0/1">John G. Baker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bugli_M/0/1/0/all/0/1">Matteo Bugli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chan_C/0/1/0/all/0/1">Chi-kwan Chan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Davelaar_J/0/1/0/all/0/1">Jordy Davelaar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zanna_L/0/1/0/all/0/1">Luca Del Zanna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Etienne_Z/0/1/0/all/0/1">Zachariah B. Etienne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fragile_P/0/1/0/all/0/1">P. Chris Fragile</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kelly_B/0/1/0/all/0/1">Bernard J. Kelly</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liska_M/0/1/0/all/0/1">Matthew Liska</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Markoff_S/0/1/0/all/0/1">Sera Markoff</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McKinney_J/0/1/0/all/0/1">Jonathan C. McKinney</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mishra_B/0/1/0/all/0/1">Bhupendra Mishra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Noble_S/0/1/0/all/0/1">Scott C. Noble</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olivares_H/0/1/0/all/0/1">H&#xe9;ctor Olivares</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Prather_B/0/1/0/all/0/1">Ben Prather</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rezzolla_L/0/1/0/all/0/1">Luciano Rezzolla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ryan_B/0/1/0/all/0/1">Benjamin R. Ryan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stone_J/0/1/0/all/0/1">James M. Stone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tomei_N/0/1/0/all/0/1">Niccol&#xf2; Tomei</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+White_C/0/1/0/all/0/1">Christopher J. White</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Younsi_Z/0/1/0/all/0/1">Ziri Younsi</a>, The <aRead More →

Simulations of imaging the event horizon of Sagittarius A* from space. (arXiv:1904.04934v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Roelofs_F/0/1/0/all/0/1">Freek Roelofs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Falcke_H/0/1/0/all/0/1">Heino Falcke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brinkerink_C/0/1/0/all/0/1">Christiaan Brinkerink</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moscibrodzka_M/0/1/0/all/0/1">Monika Mo&#x15b;cibrodzka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gurvits_L/0/1/0/all/0/1">Leonid I. Gurvits</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martin_Neira_M/0/1/0/all/0/1">Manuel Martin-Neira</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kudriashov_V/0/1/0/all/0/1">Volodymyr Kudriashov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Klein_Wolt_M/0/1/0/all/0/1">Marc Klein-Wolt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tilanus_R/0/1/0/all/0/1">Remo Tilanus</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kramer_M/0/1/0/all/0/1">Michael Kramer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rezzolla_L/0/1/0/all/0/1">Luciano Rezzolla</a> It has been proposed that Very Long Baseline Interferometry (VLBI) at sub-millimeter waves will allow us to image the shadow of the black hole in the center of our Milky Way, Sagittarius A* (Sgr A*), and thereby test basic predictions of general relativity. This paper presents imaging simulations of a new Space VLBI mission concept. An initial designRead More →

Too Big To Fail in Light of Gaia. (arXiv:1904.04939v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kaplinghat_M/0/1/0/all/0/1">Manoj Kaplinghat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valli_M/0/1/0/all/0/1">Mauro Valli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yu_H/0/1/0/all/0/1">Hai-Bo Yu</a> We point out an anti-correlation between the central dark matter (DM) densities of the bright Milky Way dwarf spheroidal galaxies (dSphs) and their orbital pericenter distances inferred from Gaia data. The dSphs that have not come close to the Milky Way center (like Fornax, Carina and Sextans) are less dense in DM than those that have come closer (like Draco and Ursa Minor). The same anti-correlation cannot be inferred for the ultra-faint dSphs due to large scatter. Including ultra-faints, a trend that dSphs with more extendedRead More →

The stellar halo of the Milky Way traced by blue horizontal-branch stars in the Subaru Hyper Suprime-Cam Survey. (arXiv:1904.04966v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Fukushima_T/0/1/0/all/0/1">Tetsuya Fukushima</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiba_M/0/1/0/all/0/1">Masashi Chiba</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tanaka_M/0/1/0/all/0/1">Mikito Tanaka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hayashi_K/0/1/0/all/0/1">Kohei Hayashi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Homma_D/0/1/0/all/0/1">Daisuke Homma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Okamoto_S/0/1/0/all/0/1">Sakurako Okamoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Komiyama_Y/0/1/0/all/0/1">Yutaka Komiyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tanaka_M/0/1/0/all/0/1">Masayuki Tanaka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arimoto_N/0/1/0/all/0/1">Nobuo Arimoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matsuno_T/0/1/0/all/0/1">Tadafumi Matsuno</a> We report on the global structure of the Milky Way (MW) stellar halo up to its outer boundary based on the analysis of blue-horizontal branch stars (BHBs). These halo tracers are extracted from the $(g,r,i,z)$ band multi-photometry in the internal data release of the on-going Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) surveyed over $sim550$~deg$^2$ area.Read More →

Transiting Planets near the Snow Line from Kepler. I. Catalog. (arXiv:1904.04980v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kawahara_H/0/1/0/all/0/1">Hajime Kawahara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masuda_K/0/1/0/all/0/1">Kento Masuda</a> We present a comprehensive catalog of cool (period $Pgtrsim 2,mathrm{yr}$) transiting planet candidates in the four-year light curves from the prime kepler mission. Most of the candidates show only one or two transits and have largely been missed in the original Kepler Object of Interest catalog. Our catalog is based on all known such candidates in the literature as well as new candidates from the search in this paper, and provides a resource to explore the planet population near the snow line of Sun-like stars. We homogeneouslyRead More →

Magnetar as Central Engine of Gamma-Ray Bursts: Central Engine-Jet Connection, Wind-Jet Energy Partition, and Origin of Some Ultra-Long Bursts. (arXiv:1904.04984v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zou_L/0/1/0/all/0/1">Le Zou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhou_Z/0/1/0/all/0/1">Zi-Min Zhou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xie_L/0/1/0/all/0/1">Lang Xie</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_L/0/1/0/all/0/1">Lu-Lu Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+LV_H/0/1/0/all/0/1">Hou-Jun LV</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhong_S/0/1/0/all/0/1">Shu-Qing Zhong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_Z/0/1/0/all/0/1">Zhen-Jie Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liang_E/0/1/0/all/0/1">En-Wei Liang</a> Gamma-ray burst (GRB) central engines and jet production mechanisms are still open questions. Assuming that the shallow decay segments of canonical X-ray afterglow lightcurves of {em Swift} GRBs are attributed to the magnetic dipole (MD) radiations of newly-born magnetars, we derive the parameters of the magnetars and explore their possible relations to jet and MD wind emission. We show thatRead More →

Magnetohydrodynamics in a Cylindrical Shearing Box. (arXiv:1904.05032v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Suzuki_T/0/1/0/all/0/1">Takeru K. Suzuki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Taki_T/0/1/0/all/0/1">Tetsuo Taki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Suriano_S/0/1/0/all/0/1">Scott S. Suriano</a> We develop a framework for magnetohydrodynamical (MHD) simulations in a local cylindrical shearing box by extending the formulation of the Cartesian shearing box. We construct shearing-periodic conditions at the radial boundaries of a simulation box from the conservation relations of the basic MHD equations. We demonstrate quasi-steady mass accretion, which cannot be handled by the standard Cartesian shearing box model, with an ideal MHD simulation in a vertically unstratified cylindrical shearing box up to 200 rotations with (i) net vertical magnetic flux, (ii) a locally isothermalRead More →

Role of Landau-Rabi quantization of electron motion on the crust of magnetars within the nuclear energy density functional theory. (arXiv:1904.05045v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mutafchieva_Y/0/1/0/all/0/1">Y. D. Mutafchieva</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chamel_N/0/1/0/all/0/1">N. Chamel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stoyanov_Z/0/1/0/all/0/1">Zh. K. Stoyanov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pearson_J/0/1/0/all/0/1">J. M. Pearson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mihailov_L/0/1/0/all/0/1">L. M. Mihailov</a> Magnetic fields of order $10^{15}$ G have been measured at the surface of some neutron stars, and much stronger magnetic fields are expected to be present in the solid region beneath the surface. The effects of the magnetic field on the equation of state and on the composition of the crust due to Landau-Rabi quantization of electron motion are studied. Both the outer and innerRead More →

Kompaneets equation for neutrinos: Application to neutrino heating in supernova explosions. (arXiv:1904.05047v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Suwa_Y/0/1/0/all/0/1">Yudai Suwa</a> (Kyoto Sangyo Univ. and YITP, Kyoto Univ.), <a href="http://arxiv.org/find/astro-ph/1/au:+Tahara_H/0/1/0/all/0/1">Hiroaki W. H. Tahara</a> (RESCEU, Univ. of Tokyo), <a href="http://arxiv.org/find/astro-ph/1/au:+Komatsu_E/0/1/0/all/0/1">Eiichiro Komatsu</a> (MPA, Garching and Kavli IPMU, Univ. of Tokyo) We derive a `Kompaneets equation’ for neutrinos, which describes how the distribution function of neutrinos interacting with matter deviates from a Fermi-Dirac distribution with zero chemical potential. To this end, we expand the collision integral in the Boltzmann equation of neutrinos up to second order in energy transfer between matter and neutrinos. The distortion of the neutrino distribution function changes the rateRead More →

A Gravitational Ising Model for the Statistical Bias of Galaxies. (arXiv:1904.05048v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Repp_A/0/1/0/all/0/1">Andrew Repp</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Szapudi_I/0/1/0/all/0/1">Istv&#xe1;n Szapudi</a> Evaluation of gravitational theories by means of cosmological data suffers from the fact that galaxies are biased tracers of dark matter. Current bias models focus primarily on high-density regions, whereas low-density regions carry significant amounts of information relevant to the constraint of dark energy and alternative gravity theories. Thus, proper treatment of both high and low densities is important for future surveys. Accordingly, we here present an interactionless Ising model for this bias, and we demonstrate that it exhibits a remarkably good fit to both Millennium SimulationRead More →

Stars and exoplanets in Stokes IQUV: a decadal opportunity for HIRES at the ELT. (arXiv:1904.05075v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Strassmeier_K/0/1/0/all/0/1">Klaus G. Strassmeier</a> We proposed that the European ELT will be equipped with an ultra-high-precision polarimetric light feed as part of its high resolution optical and near-IR spectrograph HIRES. Such a feed is unique among the new ELTs and only possible in a rotationally symmetric focus of the telescope. The ELT’s f/4.4 intermediate focus near M4 could provide such a capability with a polarimetric sensitivity of down to 10^(-5) for the brightest targets. Among the new science steps forward with HIRES-Pol at the 39m ELT would be theRead More →

Delineating the properties of matter in cold, dense QCD. (arXiv:1904.05080v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kojo_T/0/1/0/all/0/1">Toru Kojo</a> The properties of dense QCD matter are delineated through the construction of equations of state which should be consistent with QCD calculations in the low and high density limits, nuclear laboratory experiments, and the neutron star observations. These constraints, together with the causality condition of the sound velocity, are used to develop the picture of hadron-quark continuity in which hadronic matter continuously transforms into quark matter (modulo small 1st order phase transitions). For hadronic matter (at baryon density nB > ~2n0 with n0 ~ 0.16 fm^(-3) being the nuclear saturation density)Read More →

Fermionic decay of a massive scalar in the early Universe. (arXiv:1904.05084v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Lankinen_J/0/1/0/all/0/1">Juho Lankinen</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Malmi_J/0/1/0/all/0/1">Joonas Malmi</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Vilja_I/0/1/0/all/0/1">Iiro Vilja</a> We derive a curved space generalization of a scalar to fermion decay rate with a Yukawa coupling in expanding Friedmann-Robertson-Walker universes. This is done using the full theory of quantum fields in curved spacetime and the added-up transition probability method. It is found that in an expanding universe the usual Minkowskian decay rates are considerably modified for early times. For conformally coupled scalars the decay rate is modified by a positive additive term proportional to the inverse of mass and related to the expansionRead More →

Critical angular velocity and anisotropic mass loss of rotating stars with radiation-driven winds. (arXiv:1904.05089v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Gagnier_D/0/1/0/all/0/1">D. Gagnier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rieutord_M/0/1/0/all/0/1">M. Rieutord</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charbonnel_C/0/1/0/all/0/1">C. Charbonnel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Putigny_G/0/1/0/all/0/1">G. Putigny</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lara_F/0/1/0/all/0/1">F. Espinosa Lara</a> The understanding of the evolution of early-type stars is tightly related to that of the effects of rapid rotation. For massive stars, rapid rotation combines with their strong radiation-driven wind. The aim of this paper is to investigate two questions that are prerequisite to the study of the evolution of massive rapidly rotating stars: (i) What is the critical angular velocity of a star when radiative acceleration is significant in its atmosphere? (ii) HowRead More →

Growth Rates of the Upper-hybrid Waves for Power-law and Kappa Distributions with a Loss-cone Anisotropy. (arXiv:1904.05110v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Yasnov_L/0/1/0/all/0/1">Leonid V. Yasnov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benacek_J/0/1/0/all/0/1">Jan Ben&#xe1;&#x10d;ek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Karlicky_M/0/1/0/all/0/1">Marian Karlick&#xfd;</a> Fine structures of radio bursts play an important role in diagnostics of the solar flare plasma. Among them the zebras, which are prevalently assumed to be generated by the double plasma resonance instability, belong to the most important. In this paper we compute the growth rate of this instability for two types of the electron distribution: a) for the power-law distribution and b) for the kappa distribution, in the both cases with the loss-cone type anisotropy. We foundRead More →

Forecasts for Low Spin Black Hole Spectroscopy in Horndeski Gravity. (arXiv:1904.05112v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Tattersall_O/0/1/0/all/0/1">Oliver J. Tattersall</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Ferreira_P/0/1/0/all/0/1">Pedro G. Ferreira</a> We investigate the prospect of using black hole spectroscopy to constrain the parameters of Horndeski gravity through observations of gravitational waves from perturbed black holes. We study the gravitational waves emitted during ringdown from black holes without hair in Horndeski gravity, demonstrating the qualitative differences between such emission in General Relativity and Horndeski theory. In particular, Quasi-Normal Mode frequencies associated with the scalar field spectrum can appear in the emitted gravitational radiation. Analytic expressions for error estimates for both the black hole and Horndeski parametersRead More →

MUSE unravels the ionisation and origin of metal enriched absorbers in the gas halo of a z = 2.92 radio galaxy. (arXiv:1904.05114v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kolwa_S/0/1/0/all/0/1">S. Kolwa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vernet_J/0/1/0/all/0/1">J. Vernet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Breuck_C/0/1/0/all/0/1">C. De Breuck</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Villar_Martin_M/0/1/0/all/0/1">M. Villar-Martin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Humphrey_A/0/1/0/all/0/1">A. Humphrey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arrigoni_Battaia_F/0/1/0/all/0/1">F. Arrigoni-Battaia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gullberg_B/0/1/0/all/0/1">B. Gullberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Falkendal_T/0/1/0/all/0/1">T. Falkendal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Drouart_G/0/1/0/all/0/1">G. Drouart</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lehnert_M/0/1/0/all/0/1">M. Lehnert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wylezalek_D/0/1/0/all/0/1">D. Wylezalek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Man_A/0/1/0/all/0/1">A. Man</a> We have used the Multi-Unit Spectroscopic Explorer (MUSE) to study the circumgalactic medium (CGM) of a z = 2.92 radio galaxy, MRC 0943-242 by parametrising its emitting and absorbing gas. In both Ly$alpha$ $lambda$1216 and He II $lambda$1640 lines, we observe emission with velocity shiftsRead More →

Flow instabilities in solar jets in their upstream and downstream regimes. (arXiv:1904.05120v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Li_X/0/1/0/all/0/1">Xiaohong Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_J/0/1/0/all/0/1">Jun Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_S/0/1/0/all/0/1">Shuhong Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hou_Y/0/1/0/all/0/1">Yijun Hou</a> Using the Atmospheric Imaging Assembly 304 A images obtained from the Solar Dynamics Observatory, we study two jets which occurred during the M5.8 class flare on 2017 April 3 and the M5.5 class flare on 2016 July 23, respectively. During the M5.8 class flare, many vortex-like structures occurred in the upstream and downstream regimes of the associated jet. While the jet was ejected upwards to the corona, some dark material at its base flowed through a bright structure with aRead More →

Tentative evidence of spatially extended GeV emission from SS433/W50. (arXiv:1904.05127v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Sun_X/0/1/0/all/0/1">Xiao-Na Sun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_R/0/1/0/all/0/1">Rui-Zhi Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_B/0/1/0/all/0/1">Bing Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xi_S/0/1/0/all/0/1">Shao-Qiang Xi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_X/0/1/0/all/0/1">Xiang-Yu Wang</a> We analyze 10 years of Fermi-LAT data towards the SS433/W50 region. With the latest source catalog and diffuse background models, the gamma-ray excess from SS433/W50 is detected with a significance of 5.5{sigma} in the photon energy range of 500 MeV – 10 GeV. Our analysis indicates that an extended flat disk morphology is preferred over a point-source description, suggesting that the GeV emission region is much larger than that of the TeV emission detected by HAWC. The size ofRead More →

Off-centre carbon burning in He-accreting carbon-oxygen white dwarfs. (arXiv:1904.05130v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Wu_C/0/1/0/all/0/1">Chengyuan Wu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_B/0/1/0/all/0/1">Bo Wang</a> The carbon-oxygen white dwarf (CO WD) + He star channel is one of the promising ways for producing type Ia supernovae (SNe Ia) with short delay times. Recent studies found that carbon under the He-shell can be ignited if the mass-accretion rate of CO WD is higher than a critical rate (about 2 * 10^-6 Msun/yr), triggering an inwardly propagating carbon flame. Previous studies usually supposed that the off-centre carbon flame would reach the centre, resulting in the formation of an oxygen-neon (ONe) WD that will collapse into aRead More →