Abstract

Contributed Talk - Splinter StarClusters

Tuesday, 08 September 2026, 16:45   (MW-2050)

Dense star clusters, massive Black holes, gravitational waves

Rainer Spurzem
ARI ZAH, Univ. Heidelberg; NAOC/CAS Beijing

Nuclear and globular star clusters (NSC and GC) are spectacular self-gravitating stellar systems in our Galaxy and across the Universe - in many respects. They populate disks and spheroids of galaxies as well as almost every galactic center. In massive elliptical galaxies NSCs harbor supermassive black holes, which might influence the evolution of their host galaxies as a whole. The evolution of star clusters is not only governed by the aging of their stellar populations and simple Newtonian dynamics. For increasing particle number, unique gravitational effects of collisional many-body systems begin to dominate the early cluster evolution. We find a 50.000 solar mass intermediate mass black hole forming from stellar collisions in a young massive star cluster. Direct N-body simulations are the most computationally expensive but also the most astrophysically advanced method to simulated GC and NSC evolution, using massively parallel supercomputers with GPU acceleration. Models of NSC are presented with a supermassive star-accreting central black hole (SMBH). Stars passing near the SMBH produce a tidal disruption event, where the light curve of the TDE and the fraction of gaseous debris accreted to the SMBH depend on the orbital parameters before disruption. Our simulations provide rates of different types of TDE events as well as informations about extreme mass ratio inspirals and direct captures. Partial TDE will result in repeated events, which may have been observed already. It is expected that during the next years thousands of new TDE events will be observed by new instruments, so it is important to provide a background of computer models.