CM2 - Simulations of Relativistic Flows and Compact Objects |
Speaker_ |
Mondal, Soumen |
Co-autors |
Sandip K. Chakrabarti |
Talk _ |
Numerical Studies of the Standing and Oscillating Shocks in Accretion Flows in a pseudo-Kerr Geometry |
Abstract _ |
When matter with a constant angular momentum accretes on a black hole, the tug-of-war between the inward pointing gravitational force and the outward pointing cenrifugal force causes the formation of standing and oscillating shock waves. We use a pseudo-Newtonian approach (which we device) in which Newtonian equations are used around an object having such a potential that the geometry external to it is similar to that around a Kerr black hole. We present theoretical work based on sonic point analysis and divide the entire parameter space spanned by energy and angular momentum in terms of flow topologies. We carry out numerical simulations using SPH and show that these shocks really form. Some of them could be oscillatory and radiations from them could explain the quasi-periodic oscillations observed in black hole candidates. |