Thermal dissipation and outflows originating at shock front in viscous accretion flow around a black hole

Abstract

We use α prescription of viscosity and study steady state solutions of an accretion flow, in presence of dissipative shocks. The flow solutions depend on four initial parameters namely, E in , l H , α and f . We study all such solutions possible and divide the parameter space into regions which allow the formation of such shock waves and which do not. Then, we follow a similar study in presence of outflows. From the analysis of the resultant parameter space, we find that the dissipative shocks can still form for the values of α as high as 0.27 in small regions of the flow parameter space in absence of outflows. This value reduces to 0.2 in presence of outflows. The typical values of α appear in the range 0.01 − 0.15. The values of α reported from numerical simulations are always lower than 0.1. This signifies that viscosity parameter in accretion flows is low enough to form dissipative shocks, both in presence and absence of outflows. This supports our claim that shocks could be omnipresent. It was also found that a dissipation factor of f > 0.3 does not produce shocks in significant region of the flow parameter space and hence, these values are not physically relevant. Likewise, at the maximum, ∼ 13% of inflowing matter can be ejected as outflows at the CENBOL.