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相关论文: The core helium flash revisited: I. One and two-di…

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We present evolutionary models of massive, accreting population III stars with constant and variable accretion rates until the end of silicon burning, with final masses of 1000 - 3000 Msol. In all our models, after the core-hydrogen-burning…

太阳与恒星天体物理 · 物理学 2023-09-14 D. Nandal , E. Farrell , G. Buldgen , G. Meynet , S. Ekstrom

Asteroseismology of non-radial pulsations in Hot B Subdwarfs (sdB stars) offers a unique view into the interior of core-helium-burning stars. Ground-based and space-borne high precision light curves allow for the analysis of pressure and…

太阳与恒星天体物理 · 物理学 2017-11-08 J. -T. Schindler , Elizabeth M. Green , W. David Arnett

We compare evolved stellar models, which match Procyons mass and position in the HR diagram, to current ground-based asteroseismic observations. Diffusion of helium and metals along with two conventional core overshoot descriptions and the…

太阳与恒星天体物理 · 物理学 2015-06-19 D. B. Guenther , P. Demarque , M Gruberbauer

We perform for the first time a 3D hydrodynamics simulation of the evolution of the last minutes pre-collapse of the oxygen shell of a fast-rotating massive star. This star has an initial mass of 38 M$_\odot$, a metallicity of $\sim$1/50…

The purpose of this work is to explore the evolution of helium-core white dwarf stars in a self-consistent way with the predictions of detailed non-gray model atmospheres and element diffusion. To this end, we consider helium-core white…

天体物理学 · 物理学 2009-11-06 A. M. Serenelli , L. G. Althaus , R. D. Rohrmann , O. G. Benvenuto

The outer envelopes of massive ($M\gtrsim10\,M_{\odot}$) stars exhibit large increases in opacities from forests of lines and ionization transitions (particularly from iron and helium) that trigger near-surface convection zones.…

太阳与恒星天体物理 · 物理学 2023-07-19 William Schultz , Lars Bildsten , Yan-Fei Jiang

All evolved stars with masses M <2 solar masses undergo an initiating off-center helium core flash in their 0.48 solar mass He core as they ascend the red giant branch (RGB). This off-center flash is the first of a few successive helium…

太阳与恒星天体物理 · 物理学 2015-06-03 Lars Bildsten , Bill Paxton , Kevin Moore , Phillip J. Macias

We study the formation, evolution and collapse of dense cores by tracking structures in a magnetohydrodynamic simulation of a star-forming cloud. We identify cores using the dendrogram algorithm and utilize machine learning techniques,…

Broadening and asymmetry of spectral lines in slowly rotating late A-type stars provide evidence for high-amplitude convective motions. The properties of turbulence observed in the A-star atmospheres are not understood theoretically and…

天体物理学 · 物理学 2015-06-24 O. Kochukhov , B. Freytag , N. Piskunov , M. Steffen

Context. The evolution of massive stars is strongly influenced by internal mixing processes such as semiconvection, convective core overshooting, and rotationally induced mixing. None of these is currently well constrained. Aims. We…

太阳与恒星天体物理 · 物理学 2019-05-29 Abel Schootemeijer , Norbert Langer , Nathan J. Grin , Chen Wang

We investigate the evolution, final fate, and nucleosynthetic yields of rotating and non-rotating very massive stars (VMS) of zero metallicity. First we address the issue of mass loss during hydrogen burning due to vibrational…

天体物理学 · 物理学 2009-10-31 A. Heger , I. Baraffe , C. L. Fryer , S. E. Woosley

We discuss the lifetimes and evolution of clumps and cores formed as turbulent density fluctuations in nearly isothermal molecular clouds. In the non-magnetic case, clumps are unlikely to reach a hydrostatic state, and instead are expected…

We use molecular dynamics simulations in two dimensions to investigate the possibility that a core-softened potential can reproduce static and dynamic anomalies found experimentally in liquid water: (i) the increase in specific volume upon…

软凝聚态物质 · 物理学 2009-10-31 A. Scala , M. Reza Sadr-Lahijany , N. Giovambattista , S. V. Buldyrev , H. E. Stanley

We perform two-dimensional numerical simulations of core convection for zero-age-main-sequence stars covering a mass range from 3 $M_\odot$ to 20 $M_\odot$. The simulations are performed with the fully compressible time-implicit code MUSIC.…

太阳与恒星天体物理 · 物理学 2023-01-18 I. Baraffe , J. Clarke , A. Morison , D. G. Vlaykov , T. Constantino , T. Goffrey , T. Guillet , A. Le Saux , J. Pratt

We perform three dimensional radiation hydrodynamic simulations of the structure and dynamics of radiation dominated envelopes of massive stars at the location of the iron opacity peak. One dimensional hydrostatic calculations predict an…

太阳与恒星天体物理 · 物理学 2015-11-04 Yan-Fei Jiang , Matteo Cantiello , Lars Bildsten , Eliot Quataert , Omer Blaes

Massive stars have a strong impact on their surroundings, in particular when they produce a core-collapse supernova at the end of their evolution. In these proceedings, we review the general evolution of massive stars and their properties…

太阳与恒星天体物理 · 物理学 2018-02-22 Raphael Hirschi , David Arnett , Andrea Cristini , Cyril Georgy , Casey Meakin , Ian Walkington

We present the first 3D simulation of the last minutes of oxygen shell burning in an 18 solar mass supernova progenitor up to the onset of core collapse. A moving inner boundary is used to accurately model the contraction of the silicon and…

太阳与恒星天体物理 · 物理学 2016-12-21 Bernhard Müller , Maxime Viallet , Alexander Heger , Hans-Thomas Janka

We conduct a series of numerical experiments into the nature of three-dimensional (3D) hydrodynamics in the postbounce stalled-shock phase of core-collapse supernovae using 3D general-relativistic hydrodynamic simulations of a…

高能天体物理现象 · 物理学 2015-08-06 E. Abdikamalov , C. D. Ott , D. Radice , L. F. Roberts , R. Haas , C. Reisswig , P. Moesta , H. Klion , E. Schnetter

We consider a high density region of the helium phase diagram, where the nuclei form a Bose-Einstein condensate rather than a classical plasma or a crystal. Helium in this phase may be present in helium-core white dwarfs. We show that in…

核理论 · 物理学 2012-06-08 Paulo F. Bedaque , Evan Berkowitz , Aleksey Cherman

This is a sketch of a 321D approximation for stellar convection which is nonlocal, and thus has nonzero fluxes of KE (to be published in more detail elsewhere). Boundary conditions are discussed in a fluid dynamics context (i.e.,…

太阳与恒星天体物理 · 物理学 2017-08-23 W. David Arnett