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arXiv · 2303.10115

3D hydrodynamics simulations of core convection in supermassive main-sequence stars

Simon Blouin·Huaqing Mao·Tyrone E. Woods·Pavel Denissenkov·Paul R. Woodward·Falk Herwig
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Abstract

Supermassive stars are Population III stars with masses exceeding $10^4\,M_{\odot}$ that could be the progenitors of the first supermassive black holes. Their interiors are in a regime where radiation pressure dominates the equation of state. In this work, we use the explicit gas dynamics code PPMstar to simulate the hydrogen-burning core of a $10^4\,M_{\odot}$ supermassive main-sequence star. These are the first 3D hydrodynamics simulations of core convection in supermassive stars. We perform a series of ten simulations at different heating rates and on Cartesian grids with resolutions of $768^3$, $1152^3$ and $1728^3$. We examine different properties of the convective flow, including its large-scale morphology, its velocity spectrum and its mixing properties. We conclude that the radiation pressure-dominated nature of the interior does not noticeably affect the behaviour of convection compared to the case of core convection in a massive main-sequence star where gas pressure dominates. Our simulations also offer support for the use of mixing-length theory in 1D models of supermassive stars.

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Simon Blouin, Huaqing Mao, Tyrone E. Woods, Pavel Denissenkov, Paul R. Woodward, Falk Herwig. 2023-03-17. 3D hydrodynamics simulations of core convection in supermassive main-sequence stars. https://doi.org/10.1093/mnras%2Fstad846

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