Estimation and Effects of the mass outflow rate from shock compressed flow around compact objects

Abstract

Outflows are common in many astrophysical systems which contain black holes and neutron stars. Difference between stellar outflows and outflows from these systems is that the outflows in these systems have to form out of the inflowing material only. The inflowing material can form a hot and dense cloud surrounding the compact object, either because of a centrifugal barrier, or a denser barrier due to pair plasma or pre-heating effects. This barrier behaves like a stellar surface as far as the mass loss is concerned. We estimate the outflow rate from the regions of shock compressed flow. The outflow rate is directly related to the compression ratio of the gas at the shocks. These estimated rates roughly match the rates in real observations as well as those obtained from numerical experiments. In special geometries, where the solid angle of the outflow is higher, the disk evacuation takes place creating quiescence states. Outflows are shown to be important in deciding the spectral states and Quasi Periodic Oscillations (QPO)s of observed X-rays.