Non-ideal magnetohydrodynamics versus turbulence – I. Which is the dominant process in protostellar disc formation?

2020/05/11 by James Wurster, Benjamin T. Lewis · 1 citation
Chemistry · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Classical mechanics #Geometry #Ideal (ethics) #Magnetic field #Magnetohydrodynamics #Mechanics #Molecular Spectroscopy and Structure #Physics #Protostar #Rotation (mathematics) #Star formation #Stars #Stellar, planetary, and galactic studies #Turbulence #astro-ph.EP #astro-ph.GA #astro-ph.SR

paper · pdf · doi:10.1093/mnras/staa1339

Accepted for publication in MNRAS. 12 pages, 8 figures

arxiv created 2020/05/11 · openalex publication_date 2020/05/15 · openalex created_date 2020/05/21 · arxiv updated 2020/06/03 · openalex updated_date 2026/08/06

Abstract

ABSTRACT Non-ideal magnetohydrodynamics (MHD) is the dominant process. We investigate the effect of magnetic fields (ideal and non-ideal) and turbulence (sub- and transsonic) on the formation of circumstellar discs that form nearly simultaneously with the formation of the protostar. This is done by modelling the gravitational collapse of a 1 M⊙ gas cloud that is threaded with a magnetic field and imposed with both rotational and turbulent velocities. We investigate magnetic fields that are parallel/antiparallel and perpendicular to the rotation axis, two rotation rates, and four Mach numbers. Disc formation occurs preferentially in the models that include non-ideal MHD where the magnetic field is antiparallel or perpendicular to the rotation axis. This is independent of the initial rotation rate and level of turbulence, suggesting that subsonic turbulence plays a minimal role in influencing the formation of discs. Aside from first core outflows that are influenced by the initial level of turbulence, non-ideal MHD processes are more important than turbulent processes during the formation of discs around low-mass stars.

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• Non-ideal magnetohydrodynamics versus turbulence II: Which is the dominant process in stellar core formation?