Two‐dimensional Models of Hydrodynamical Accretion Flows into Black Holes

Abstract

We present a systematic numerical study of two-dimensional axisymmetric\naccretion flows around black holes. The flows have no radiative cooling and are\ntreated in the framework of the hydrodynamical approximation. The models\ncalculated in this study cover the large range of the relevant parameter space.\nThere are four types of flows, determined by the values of the viscosity\nparameter $\\alpha$ and the adiabatic index $\\gamma$: convective flows,\nlarge-scale circulations, pure inflows and bipolar outflows. Thermal conduction\nintroduces significant changes to the solutions, but does not create a new flow\ntype. Convective accretion flows and flows with large-scale circulations have\nsignificant outward-directed energy fluxes, which have important implications\nfor the spectra and luminosities of accreting black holes.\n