Reconstructing the history of Terzan 5 through hydrodynamical N-body simulations

The discovery of complex stellar populations in the massive systems Terzan 5 and Liller 1 has raised intriguing questions about their origin and possible connection to the Galactic Bulge's formation. Despite their Globular Cluster appearance, the presence of subpopulations with significantly different ages (several Gyrs) and metallicities (∼1 dex) suggests they are not genuine globular, which typically have a single age and minor (if any) metallicity spread. These surprising properties support the self-enrichment scenario, implying they could be remnants of primordial massive structures capable of retaining supernova ejecta within their potential well. Few alternative hypotheses about their origin have been suggested in the literature. However, while some of them have been naturally discarded by the discovered properties of these two systems, a viable alternative possibility remains: a massive genuine Globular Cluster that accreted a Giant Molecular Cloud. The aim of this thesis is to explore the scenario in the case of Terzan5 by using a hydrodynamical N-body simulation. The simulation setup follows the "wind-tunnel" scheme as implemented in Calura et al. (2019) where a GMC within the Milky Way's Galactic Bulge interacts with a self-gravitating stellar system (the proto-Terzan 5) situated in a medium with physical conditions like those of the Bulge. The simulations implement three key physical processes adopted by Calura et al. (2022, 2024): star formation; stellar feedback; and the cooling scheme. The main result of this work is that, independently on the initial mass of the accreting star cluster and the velocity infall of the GMC, the mass of the new stellar population formed from the accretion of the Cloud always remains orders of magnitude below the mass of the young sub-population observed in Terzan5, thus severely challenging the hypothesis that this could be the formation channel of this stellar system.