2004/09/19 by Mark R. Krumholz, Christopher F. McKee, Richard I. Klein · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/426051
published as Astrophys.J. 618 (2005) 757-768 · 34 pages, 10 figures, accepted for publication in ApJ
arxiv created 2004/09/19 · arxiv updated 2009/12/01
The classical Bondi-Hoyle formula gives the accretion rate onto a point particle of a gas with a uniform density and velocity. However, the Bondi-Hoyle problem considers only gas with no net vorticity, while in a real astrophysical situation accreting gas invariably has at least a small amount of vorticity. We therefore consider the related case of accretion of gas with constant vorticity, for the cases of both small and large vorticity. We confirm the findings of earlier two dimensional simulations that even a small amount of vorticity can substantially change both the accretion rate and the morphology of the gas flow lines. We show that in three dimensions the resulting flow field is non-axisymmetric and time dependent. The reduction in accretion rate is due to an accumulation of circulation near the accreting particle. Using a combination of simulations and analytic treatment, we provide an approximate formula for the accretion rate of gas onto a point particle as a function of the vorticity of the surrounding gas.