2002/08/28 by D. Proga, Daniel Proga, Mitchell C. Begelman +1 · 2 citations
Physics and Astronomy · #Accretion (finance) #Angular momentum #Astrophysical Phenomena and Observations #Dust and Plasma Wave Phenomena #Intermediate polar #Inviscid flow #Polar #Pulsars and Gravitational Waves Research #Rotational symmetry #Specific relative angular momentum #Torus #astro-ph
paper · pdf · doi:10.1086/344537
published as Astrophys.J. 582 (2003) 69-81 · LaTeX,to appear in ApJ
arxiv created 2002/08/28 · openalex publication_date 2003/01/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report on the first phase of our study of slightly rotating accretion flows onto black holes. We consider inviscid accretion flows with a spherically symmetric density distribution at the outer boundary, but with spherical symmetry broken by the introduction of a small, latitude-dependent angular momentum. We study accretion flows by means of numerical two-dimensional, axisymmetric, hydrodynamical simulations. Our main result is that the properties of the accretion flow do not depend as much on the outer boundary conditions (i.e., the amount as well as distribution of the angular momentum) as on the geometry of the nonaccreting matter. The material that has too much angular momentum to be accreted forms a thick torus near the equator. Consequently, the geometry of the polar region, where material is accreted (the funnel), and the mass accretion rate through it are constrained by the size and shape of the torus. Our results show one way in which the mass accretion rate of slightly rotating gas can be significantly reduced compared to the accretion of nonrotating gas (i.e., the Bondi rate) and set the stage for calculations that will take into account the transport of angular momentum and energy.