| Abstract : | The merging of two black holes produces gravitational wave which carries energy and angular momentum of the system. Finally, when they merge in a violent collision, with enough of released energy, the newly formed black hole would be kicked away from the center of the galaxy or even out of the entire galaxy in the opposite side of the location with the highest gravitational waves. But, when a heavy particle moves through a sea of much lighter particles, it experiences a retarding force because of the exchange of angular momentum and energy. Therefore the dynamical friction tries to reduce the speed of the black hole. We have studied this movement of black holes when the kick velocity is higher than the escape velocity. For this, we are assuming a Plummer density profile and built a semi-analytic model to calculate this. We have checked in the cases of galaxies as well as globular clusters, if the dynamical friction can reduce the velocity below the escape velocity or not. If it can't then and the black hole is kicked out, then does it stay within the halo or it crosses that. Our study can give an indication of whether we can find orphan black holes in the universe. |
