Accretion onto a moving black hole: An exact solution

The author presents the results of recent research into the steady-state accretion of homogeneous matter moving with uniform velocity onto a black hole. An adiabatic equation of state with constant γ is assumed. In the Newtonian regime, he finds broad agreement with previous numerical results, while results for relativistic flows agree qualitatively with the Newtonian results. He also presents an exact nonspherical relativistic flow solution for the equation of state P = i (sound speed = light speed), that is valid for both Schwarzschild and Kerr black holes. The flow patterns are given in three space dimensions, but the accretion rate is independent of the angle between the spin axis and the flow direction