NON-AXISYMMETRICAL RELATIVISTIC BONDI-HOYLE ACCRETION ON TO A SCHWARZSCHILD BLACK-HOLE

We present the results of an exhaustive numerical study of fully relat ivistic non-axisymmetric Bondi-Hoyle accretion on to a moving Schwarzs child black hole. We have solved the equations of general relativistic hydrodynamics with a high-resolution shock-capturing numerical scheme based on a linearized Riemann solver. The numerical code was previous ly used to study axisymmetric flow configurations past a Schwarzschild black hole. We have analysed and discussed the flow morphology for a sample of asymptotically high Mach number models. The results of this work reveal that initially asymptotic uniform flows always accrete on to the hole in a stationary way, which closely resembles the previous axisymmetric patterns. This is in contrast with some Newtonian numeric al studies where violent flip-flop instabilities were found. As discus sed in the text, the reason can be found in the initial conditions use d in the relativistic regime, as they cannot exactly duplicate the pre vious Newtonian setups where the instability appeared. The dependence of the final solution on the inner boundary condition as well as on th e grid resolution has also been studied. Finally, we have computed the accretion rates of mass and linear and angular momentum.