2006/06/08 by Igor V. Igumenshchev, I. V. Igumenshchev · 4 citations
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astrophysical Phenomena and Observations #Astrophysics #Buoyancy #Computational physics #High-pressure geophysics and materials #Laser-Plasma Interactions and Diagnostics #Magnetic field #Magnetohydrodynamics #Mechanics #Physics #Supersonic speed #Turbulence #astro-ph
paper · pdf · doi:10.1086/506603
published as Astrophys.J.649:361-372,2006 · 31 pages, 7 figures attached in jpg-format; to appear in ApJ
arxiv created 2006/06/08 · openalex publication_date 2006/09/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Spherical (nonrotating) accretion flows with small-scale magnetic fields have been investigated using three-dimensional, time-dependent MHD simulations. These simulations have been designed to model high-resolution (quasi-) steady accretion flows in a wedge computational domain that represents a small fraction of the full spherical domain. Subsonic and supersonic (superfast-magnetosonic) accretion flows have been considered. Two accretion regimes have been studied: conservative, or radiatively inefficient; and nonconservative, in which the heat released in magnetic reconnections is completely lost. The flows in both regimes are turbulent. They show flattened radial density profiles and reduction of the accretion velocities and mass accretion rates in comparison with hydrodynamic Bondi flows. In the conservative regime, the turbulence is more intensive and supported mostly by thermal convection. In the nonconservative regime, the turbulence is less intensive and supported by magnetic buoyancy and various magnetic interactions. We have concluded that steady, supersonic spherical accretion cannot develop in the presence of small-scale magnetic fields.