On accretion from an inhomogeneous medium

Abstract

We consider hypersonic accretion flow in two dimensions from an infinite medium which contains a small density and/or velocity gradient. To first order in ra/h, where ra is the accretion radius and h the scale of the gradient, the accretion rate is unaffected and the accreted angular momentum is zero. Thus previous estimates of the amount of angular momentum accreted may severely overestimate the actual value.