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Related papers: Implicit hydrodynamic simulations of stellar inter…

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Artificially increasing the luminosity and the thermal diffusivity of a model is a common tactic adopted in hydrodynamical simulations of stellar convection. In this work, we analyse the impact of these artificial modifications on the…

Solar and Stellar Astrophysics · Physics 2022-04-20 A. Le Saux , T. Guillet , I. Baraffe , D. G. Vlaykov , T. Constantino , J. Pratt , T. Goffrey , M. Sylvain , V. Réville , A. S. Brun

The special computational challenges of simulating 3-D hydrodynamics in deep stellar interiors are discussed, and numerical algorithmic responses described. Results of recent simulations carried out at scale on the NSF's Blue Waters machine…

Solar and Stellar Astrophysics · Physics 2019-10-02 Paul R. Woodward , Pei-Hung Lin , Huaqing Mao , Robert Andrassy , Falk Herwig

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

Because Cepheid variable stars have long been used as a cosmic benchmark, the accuracy of stellar evolution models for Cepheids have wide-reaching effects. Our goal is to provide a detailed multi-dimensional picture of hydrodynamic…

Solar and Stellar Astrophysics · Physics 2025-06-25 Maxime Stuck , Jane Pratt , Isabelle Baraffe , Joyce Ann Guzik , Mary-Geer Dethero , Dimitar Vlaykov , Tom Goffrey , Arthur Le Saux

Context. Recent, nonlinear simulations of wave generation and propagation in full-star models have been carried out in the anelastic approximation using spectral methods. Although it makes long time steps possible, this approach excludes…

Solar and Stellar Astrophysics · Physics 2020-09-15 L. Horst , P. V. F. Edelmann , R. Andrassy , F. K. Roepke , D. M. Bowman , C. Aerts , R. P. Ratnasingam

We apply a computationally efficient technique to validate the global structure of the pulsar magnetosphere. In this first of a series of studies, a 3D, computationally intensive, implicit Crank-Nicolson finite-difference scheme is…

High Energy Astrophysical Phenomena · Physics 2018-04-23 Sushilkumar Sreekumar , Eric M. Schlegel

We describe and discuss hydrodynamic simulations of the core helium flash using an initial model of a 1.25 M_sol star with a metallicity of 0.02 near at its peak. Past research concerned with the dynamics of the core helium flash is…

Solar and Stellar Astrophysics · Physics 2009-05-01 M. Mocak , E. Mueller , A. Weiss , K. Kifonidis

There is strong observational evidence that the convective cores of intermediate-mass and massive main sequence stars are substantially larger than those predicted by standard stellar-evolution models. However, it is unclear what physical…

Solar and Stellar Astrophysics · Physics 2024-08-20 R. Andrassy , G. Leidi , J. Higl , P. V. F. Edelmann , F. R. N. Schneider , F. K. Roepke

A hydrodynamic formulation of the evolution of large-scale structure in the Universe is presented. It relies on the spatially coarse-grained description of the dynamical evolution of a many-body gravitating system. Because of the assumed…

Astrophysics · Physics 2009-10-31 Alvaro Dominguez

Much progress has recently been made in understanding and quantifying vertical mixing induced by double-diffusive instabilities such as fingering convection (usually called thermohaline convection) and oscillatory double-diffusive…

Earth and Planetary Astrophysics · Physics 2014-01-07 Pascale Garaud

We review recent results of stellar pulsation modelling that show that even very simple one-dimensional models for time dependent turbulent energy diffusion and convection provide a substantial improvement over purely radiative models.

Astrophysics · Physics 2007-05-23 J. Robert Buchler , Philip Yecko , Zoltan Kollath , Marie-Jo Goupil

When the primary star in a close binary system evolves into a giant and engulfs its companion, its core and the companion temporarily orbit each other inside a common envelope. Drag forces transfer orbital energy and angular momentum to the…

Solar and Stellar Astrophysics · Physics 2022-12-15 Friedrich K. Roepke , Orsola De Marco

This paper presents the results of a set of radiative hydrodynamic (RHD) simulations of convection in the near-surface regions of a rapidly rotating star. The simulations use microphysics consistent with stellar models, and include the…

Solar and Stellar Astrophysics · Physics 2020-06-10 Frank Robinson , Joel Tanner , Sarbani Basu

Hydrodynamical simulations of stellar interactions require stable models of stars as initial conditions. Such initial models, however, are difficult to construct for giant stars because of the wide range in spatial scales of the hydrostatic…

Solar and Stellar Astrophysics · Physics 2017-02-22 Sebastian T. Ohlmann , Friedrich K. Roepke , Rüdiger Pakmor , Volker Springel

Convection is the most important physical process that determines the structure of the envelopes of cool stars. It influences the surface radiation flux and the shape of observed spectral line profiles and is responsible for both generating…

Solar and Stellar Astrophysics · Physics 2009-12-03 F. Kupka

Recently 3D hydrodynamical simulations of stellar surface convection have become feasible thanks to advances in computer technology and efficient numerical algorithms. Available observational diagnostics indicate that these models are…

Astrophysics · Physics 2007-05-23 Martin Asplund , Remo Collet

We present a new method to obtain more realistic initial conditions for N-body simulations of young star clusters. We start from the outputs of hydrodynamical simulations of molecular cloud collapse, in which star formation is modelled with…

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the…

Solar and Stellar Astrophysics · Physics 2016-05-17 Joyce A. Guzik , T. H. Morgan , N. J. Nelson , C. Lovekin , K. Kosak , I. N. Kitiashvili , N. N. Mansour , A. Kosovichev

A high-precision two-dimensional stellar evolution code has been developed for studying solar variability due to structural changes produced by varying internal magnetic fields of arbitrary configurations. Specifically, we are interested in…

Astrophysics · Physics 2009-11-11 L. H. Li , P. Ventura , S. Basu , S. Sofia , P. Demarque

We study turbulent convection during the core helium flash close to its peak by comparing the results of two and three-dimensional hydrodynamic simulations. We use a multidimensional Eulerian hydrodynamics code based on state-of-the-art…

Astrophysics · Physics 2015-05-13 M. Mocak , E. Mueller , A. Weiss , K. Kifonidis