Work

Globular clusters (GCs) are thought to be the oldest objects in our Galaxy and in the Local Group, their age covering a large fraction of the age of the universe, and they are considered as fossil records of the time of early galaxy formation. Globular clusters are found near all galaxies (except for the smallest dwarfs) and their specific frequency (number of clusters per galaxy mass unit) differs as a function of galaxy type, which tells us about the close relation between cluster and galaxy formation (see e.g. Brodie & Strader 2006, Forbes et al. 2018, Harris et al. 2017b, Longobardi et al. 2018). It has been a long-standing challenge to follow the evolution of a massive globular cluster with self-consistent numerical simulations. Modeling has been either done by smaller than real particle numbers (e.g. Heggie 2014) or with approximate models (Monte Carlo models). For the first time (Wang et al. 2015, 2016) has carried out the – up to now - most realistic simulations of the evolution of a globular cluster with initially one million stars orbiting in the tidal field of the Milky Way for about 12 billion years. This project investigates the dynamical evolution of Globular Clusters by direct N-body simulations in the time variable Milky Way type external tidal field (potential) extracted from the up to date large scale cosmological simulation IllustrisTNG . From the publicly available IllustrisTNG data we already extract the time variable smoothed disk and halo mass distributions and will combine these data with our high precision massively parallel direct N-body code (φ-GRAPE/GPU). We will analyze in detail the close interaction between the GCs itself (collisions or strong passing by interaction, including the stellar members exchange) and the galactic central Supermassive Black Holes (SMBH) with the individual GC.