Magnetohydrodynamic Accretion Flows: Formation of Magnetic Tower Jet and Subsequent Quasi–Steady State

Abstract

We present three-dimensional magnetohydrodynamic (MHD) simulations of radiatively inefficient accretion flow around black holes. General relativistic effects are simulated by using the pseudo-Newtonian potential. We start calculations with a rotating torus threaded by localized poloidal magnetic fields with plasma-beta, a ratio of the gas pressure to the magnetic pressure, beta=10 and 100. When the bulk of torus material reaches the innermost region close to a central black hole, a magnetically driven jet emerges. This magnetic jet is derived by vertically inflating toroidal fields (``magnetic tower'') and has a two-component structure: low-beta (