Marcelo Cortes Vergara  (Chile)

Marcelo.C.Vergara@uni-heidelberg.de

Global instability by runaway collisions in nuclear stellar clusters: Numerical tests of a route for massive black hole formation

Galactic centers can harbor nuclear stellar clusters (NSCs), supermassive black holes (SMBHs), or both, and the cause of this dichotomy remains a puzzle. NSCs are the most compact and crowded stellar systems in the Universe, providing a setting for frequent collisions. Previous studies have indicated a critical mass threshold in these clusters, where collisions are commonplace and result in the formation of a massive object. Under these circumstances, it is proposed that NSCs with masses over 10^8 solar masses in virial equilibrium have longer relaxation times than collision times. Consequently, these star clusters are too compact to be stable against collisions, leading to destabilization and a collapse of most of the mass into a massive black hole. Direct simulations of this phenomenon can be challenging due to high star numbers, but Nbody6++GPU is a suitable tool for solving this problem numerically.

Supervisor:    Rainer Spurzem   (ARI)