Angular Momentum Transport from a Rotating Black Hole via Magnetohydrodynamical Accretion

Abstract

We present a new analytical approach to the study of ideal magnetohydrodynamical (MHD) accretion onto a black hole. The accretion flow ejected from the plasma sources must be trans-magnetosonic to fall into the black hole. To find such a critical solution, in the framework of the previous trans-magnetosonic analysis, we must tune the field-aligned flow parameters that are restricted by the regularity conditions at magnetosonic points. In our approach, we introduce a new parameter related to the poloidal and toroidal magnetic field components. Then, we are able to obtain trans-magnetosonic flow solutions without considering the regularity conditions; these conditions are automatically satisfied. This new method is very useful for studying the black hole magnetosphere.