Viscous dissipative two-temperature accretion flows around black holes

Abstract

General relativistic, advective, viscous, two-temperature accretion disc solutions are studied around a Schwarzschild black hole. The thermodynamics of the flow is described by the relativistic equation of state or Chattopadhyay and Ryu equation of state modified for a two-temperature regime. The cooling processes considered are bremsstrahlung, synchrotron and the Comptonization of these photons. The degeneracy of accretion solutions in the two-temperature regime is resolved using the so called ‘maximum entropy’ methodology. Utilizing this method, we analyzed the unique solutions and the corresponding spectra for a broad range of parameter space. Interplay between heating due to viscous dissipation and cooling due to different radiation mechanisms plays a significant role in determining the solution and spectrum obtained. In the end, we analyze the observation of a low luminosity AGN, NGC 3998, fitted using our model.