Miroslav Micic - Graduate Student

Physical Address:

525 Davey Laboratory
University Park, PA 16802
Phone: +1.814.863.7260
Fax: +1.814.863.9608

Mailing Address:

The Pennsylvania State University
Department of Physics
525 Davey Laboratory
University Park, PA 16802

Research Interests

I have been working with Steinn Sigurdsson and Tom Abel for the last three years. We performed a number of cosmological simulations while trying to answer questions concerning formation of structures in the universe, galaxies intermediate and supermassive black holes. Primordial stars are likely to be very massive, form in isolation and likely will leave black holes as remnants in the centers of their host dark matter halos in the mass range. Such early black holes have been speculated to be the seed black holes for the many supermassive black holes found in glaxies in the local universe. If they exist, their mergers with nearby supermassive black holes may be a prime signal for long wavelength gravitational wave detectors. We distinguish cases in which the black holes are born in the center of high redshift dark matter halos and are endowed with or without initial kick velocities. The central distributions of early black holes in present day galaxies is reduced if they are born even with moderate kicks of tens of km/s. The modest kicks allow the black holes to leave their parent halo which consequently leads to dynamical friction being less effective on the lower mass black holes as compared to their parent halos. Therefore, merger rates may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N--body simulations we quantify the role of natal kicks of black holes formed from massive metal free stars on their merger rates with supermassive black holes in present day galaxies. Our results also apply to black holes ejected by the gravitational slingshot mechanism.

Figure: Formation of supermassive black hole at the center of Galaxy through merger of primordial black holes. Trajectories show the path of black holes from redshift z=8.16 to redshift z-1.00.