Self-consistent modelling of star cluster evolution: Initial conditions and the origin of the stellar population II halo of the Milky Way

• Applicant: Professor Dr. Pavel Kroupa
• Subject Area: Astrophysics and Astronomy ; African, American and Oceania Studies
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 234732163

Only recently it became appreciated that information from the earliest phase of globular cluster (GC) evolution, the removal of the residual-gas from which the stars of a GC formed, may still be contained in present-day observational data. This provides a means to back-trace GCs to their probable initial states using self-consistent \Nbody computations. It has furthermore been suggested that the stellar population II halo of the Milky originates from dissolving star clusters and the fraction of Galactic halo stars that have formed in star clusters may be quantified. Since the oldest GCs in our Galaxy have witnessed the formation of the Milky Way (MW) and since gas-expulsion from GCs is influenced by the evolving tidal-field of the MW, the conditions GCs were exposed to at birth allow a reconstruction of the MW's formation history.We therefore aim to perform for the first-time a high-precision \Nbody study to investigate star cluster evolution self-consistently, including residual-gas expulsion, a changing tidal-field environment and classical two-body relaxation driven evolution. The results will disentangle effects driven by these physical processes and the range of allowed initial conditions, given the observational data, will be investigated. This will provide insights into the early star cluster formation processes and will constrain the detailed events of the formation of the Galaxy.

• DFG Programme: Research Grants