A NUMERICAL STUDY OF RELATIVISTIC BONDI-HOYLE ACCRETION ONTO A MOVINGBLACK-HOLE - AXISYMMETRICAL COMPUTATIONS IN A SCHWARZSCHILD BACKGROUND

A fully relativistic numerical study of nonspherical Bondi-Hoyle accre tion onto a Schwarzschild black hole is presented. The simulations are performed in axisymmetry with a high-resolution shock-capturing numer ical scheme that makes use of a linearized Riemann solver as a key ing redient to handle shock waves. A broad family of initial flow paramete rs is considered. The main differences among the accretion patterns of the different models is discussed. A detailed comparative study with a previous relativistic simulation is performed. The results of this s tudy reveal a qualitative agreement in the morphology and dynamics of the flow. However, there are important discrepancies concerning quanti tative results as the mass accretion rates. All models evolved numeric ally in this paper relax to a final steady state accretion pattern, an d, as the simulations are performed in axisymmetry, no evidence of any kind of instabilities (e.g., flip-flop) is present.