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Related papers: 3D Convective Urca Process in a Simmering White Dw…

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A toy model of the post-shock region of core-collapse supernovae is used to study the non-linear development of turbulent motions driven by convection in the presence of advection. Our numerical simulations indicate that buoyant…

Solar and Stellar Astrophysics · Physics 2018-07-18 Rémi Kazeroni , Brendan K. Krueger , Jérôme Guilet , Thierry Foglizzo , Daniel Pomarède

Shell convection driven by nuclear burning in a stellar core is a common hydrodynamic event in the evolution of many types of stars. We encounter and simulate this convection (i) in the helium core of a low-mass red giant during core helium…

Solar and Stellar Astrophysics · Physics 2015-05-27 Miroslav Mocak , Ewald Muller , Lionel Siess

We present the first three dimensional (3D) simulation of the final minutes of iron core growth in a massive star, up to and including the point of core gravitational instability and collapse. We self-consistently capture the development of…

High Energy Astrophysical Phenomena · Physics 2015-08-06 Sean M. Couch , Emmanouil Chatzopoulos , W. David Arnett , F. X. Timmes

When carbon is ignited off-center in a CO core of a super-AGB star, its burning in a convective shell tends to propagate to the center. Whether the C flame will actually be able to reach the center depends on the efficiency of extra mixing…

Solar and Stellar Astrophysics · Physics 2014-11-07 Pavel Denissenkov , James Truran , Falk Herwig , Sam Jones , Bill Paxton , Ken'ichi Nomoto , Toshio Suzuki , Hiroshi Toki

In the classical picture, electron-capture supernovae and the accretion-induced collapse of oxygen-neon white dwarfs (ONeWDs) undergo an oxygen deflagration phase before gravitational collapse produces a neutron star (NS). These types of…

Solar and Stellar Astrophysics · Physics 2016-09-28 Samuel Jones , Friedrich K. Roepke , Ruediger Pakmor , Ivo R. Seitenzahl , Sebastian T. Ohlmann , Philipp V. F. Edelmann

We perform large-scale numerical simulations of convection in 3D porous media at Rayleigh-Darcy numbers up to $Ra=8\times10^4$. To investigate the convective mixing of carbon dioxide (CO$_2$) in geological formations, we consider a…

Fluid Dynamics · Physics 2025-03-27 Marco De Paoli , Francesco Zonta , Lea Enzenberger , Eliza Coliban , Sergio Pirozzoli

A white dwarf (WD) gains substantial angular momentum during the accretion process that grows it toward a Chandrasekhar mass. It is therefore expected to be quickly rotating when it ignites as a Type Ia supernova. The thermal and shearing…

Astrophysics · Physics 2009-11-13 Anthony L. Piro

During most stages of stellar evolution the nuclear burning of lighter to heavier elements results in a radial composition profile which is stabilizing against buoyant acceleration, with light material residing above heavier material.…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. Mocák , Casey A. Meakin , E. Müller , L. Siess

Prior to the explosion of a carbon-oxygen white dwarf in a Type Ia supernova there is a long "simmering," during which the 12C + 12C reaction gradually heats the white dwarf on a long (~ 1000 yr) timescale. Piro & Bildsten showed that weak…

Astrophysics · Physics 2009-11-13 David A. Chamulak , Edward F. Brown , F. X. Timmes , Kimberly Dupczak

We discuss the effects of rotation on the evolution of accreting carbon-oxygen white dwarfs, with the emphasis on possible consequences in Type Ia supernova (SN Ia) progenitors. Starting with a slowly rotating white dwarf, we simulate the…

Astrophysics · Physics 2009-11-10 S. -C. Yoon , N. Langer

Symbiotic binaries are systems containing white dwarfs (WDs) and red giants. Symbiotic novae are those systems in which thermonuclear eruptions occur on the WD components. These are to be distinguished from events driven by accretion disk…

Solar and Stellar Astrophysics · Physics 2018-03-14 S. Starrfield , F. X. Timmes , C. Iliadis , W. R. Hix , W. D. Arnett , C. Meakin , W. M. Sparks

Type Ia supernovae have recently received considerable attention because it appears that they can be used as "standard candles" to measure cosmic distances out to billions of light years away from us. Observations of type Ia supernovae seem…

Astrophysics · Physics 2007-05-23 W. Hillebrandt , M. Reinecke , W. Schmidt , F. K. Roepke , C. Travaglio , J. C. Niemeyer

We present the first detailed three-dimensional (3D) hydrodynamic implicit large eddy simulations of turbulent convection of carbon burning in massive stars. Simulations begin with radial profiles mapped from a carbon burning shell within a…

Solar and Stellar Astrophysics · Physics 2017-08-02 Andrea Cristini , Casey Meakin , Raphael Hirschi , David Arnett , Cyril Georgy , Maxime Viallet

Classical novae are thermonuclear explosions that take place in the envelopes of accreting white dwarfs in binary systems. The material piles up under degenerate conditions, driving a thermonuclear runaway. The energy released by the suite…

Solar and Stellar Astrophysics · Physics 2016-06-29 Jordi Casanova , Jordi Jose , Enrique Garcia-Berro , Steven N. Shore

In Pop III stellar models convection-induced mixing between H- and He-rich burning layers can induce a burst of nuclear energy and thereby substantially alter the subsequent evolution and nucleosynthesis in the first massive stars. We…

Solar and Stellar Astrophysics · Physics 2020-11-04 Ondrea Clarkson , Falk Herwig

Context. Mixing by convective overshooting has long been suggested to play an important role for the amount of hydrogen available to nuclear burning in convective cores of stars. The best way to model this effect is still debated. Aims. We…

Solar and Stellar Astrophysics · Physics 2022-11-16 F. Kupka , F. Ahlborn , A. Weiss

The neutrino-heated "gain layer" immediately behind the stalled shock in a core-collapse supernova is unstable to high-Reynolds-number turbulent convection. We carry out and analyze a new set of 19 high-resolution three-dimensional (3D)…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Sean M. Couch , Christian D. Ott

We present the results of two-dimensional calculations of turbulent nuclear burning of hydrogen-rich material accreted onto a white dwarf of 1 solar mass. The main aim of the present paper is to investigate the question as to whether and…

Astrophysics · Physics 2008-11-26 A. Kercek , W. Hillebrandt , J. Truran

The extent of mixed regions around convective zones is one of the biggest uncertainties in stellar evolution. 1D overshooting descriptions introduce a free parameter ($f_{ov}$) that is in general not well constrained from observations.…

Solar and Stellar Astrophysics · Physics 2021-03-08 Johann Higl , Ewald Mueller , Achim Weiss

Based on detailed 2D and 3D numerical radiation-hydrodynamics (RHD) simulations of time-dependent compressible convection, we have studied the dynamics and thermal structure of the convective surface layers of a prototypical late-type…

Astrophysics · Physics 2009-11-07 H. -G. Ludwig , F. Allard , P. H. Hauschildt