Numerical simulations of rotating bondi accretion flows

Abstract

We explore through numerical simulations the structure formed around a black hole as a consequence of supersonic Bondi accretion with a small, finite angular momentum. The structure accompanies an accretion shock, inside which the flow is subsonic and is dissipated by the viscosity. We assume the dissipated energy is stored as entropy rather than being radiated. Although it is generally known that such advection-dominated accretion flow, as well as Bondi accretion flow, is dynamically stable in one-dimension, our numerical simulations indicate that a structure that contains the two flows is globally unstable, resulting in an oscillation with a period of similar to M-BH/M-circle dot sec. In this contribution, we describe briefly the nature of the oscillation, which may explain the low-frequency quasi-periodic oscillations with a frequency nu similar to 0.1 Hz, observed in stellar mass black hole candidates