We study the instability of standing shock wave in Black Hole Geometry by two-dimensional general relativistic hydrodynamical simulations in the equatorial plane. We show that the standing shock become unstable against non-axisymmetric perturbations in spite of stable axisymmetric perturbation.
In this conference, We focus on this shock behavior which forms spiral arm structures and rotates and oscillates quasi-periodically. We consider that this behavior might be the candidate of black hole QPO and time fluctuations of GRB prompt emission phase. We also consider why the standing shock becomes unstable against non-axisymmetric perturbations. It seems to be similar mechanism of Standing Accretion Shock Instability ( namely SASI ) which was found in supernova context. Specifically in this conference, we will explain this kind of instability and implications for Black Hole QPO. |