Abstract:
We study the time dependent properties of sub-Keplerian vis-
cous accretion flow around the black holes. We find that rotating matter
feels centrifugal barrier on the way towards the black holes and eventually,
shock transition is triggered allowing a part of the post-shock matter to
eject out as bipolar outflow. This outflowing matters are supposed to be the
precursor of relativistic jets. As viscosity is increased, shock becomes un-
steady and start to oscillate when viscosity reached its critical value. This
causes the inner part of the disk unsteady resulting periodic ejection of mat-
ter from the post-shock region. Also, the same hot and dense post-shock
matter emits high energy radiation which modulates quasi-periodically.
The power density spectra confirms this features as most of the power is
concentrated at a narrow frequency range — a characteristics (i.e. Quasi-
Periodic Oscillation) commonly seen in several outbursting black hole candidates.