Accretion and wind solutions with a variable adiabatic index and the possibilities of shock

Abstract

Using the relativistic equation of state (EOS) in which the adiabatic index γ varies smoothly from as a function radius (Basu and Mondal 2011 arXiv:1103.3330 [astro-ph]), we review accretion and wind solutions once again. We find that except for the region very near the compact object, γ does not change significantly from its non-relativistic value and therefore the EOS mostly remains non-relativistic in nature. As a consequence, the existence of two saddle-type critical points becomes a rare possibility indicating that it is an artifact of the choice of the constant ultrarelativistic . Therefore, the formation of shocks in the flow (which requires the presence of two saddle-type points) becomes very unlikely.