Analytical studies of standing shocks in accretion flows around compact objects

Abstract

Shocks in advective flows around black holes have become es- sential ingredients in explaining wide variety of observed features. We first analytically study the properties of shocks in the special case when viscosity and other dissipative processes are negligible. We compare our analytical re- sults with those obtained numerically. The agreement is generally good. In the course of development of the accretion disk models we study the effects of viscosity and different types of cooling mechanisms, such as bremsstrahlung and synchrotron coolings, in succession. We identify the region of parameter space which produces multiple sonic points and shocks separately in presence of heating and cooling effects. We quantify two critical viscosity parameters and a critical cooling factor which separate the flow topologies.