Shaping the Inner Galactic Center: The Role of Stellar Dynamics around Sagittarius A*

Abstract

This Thesis examines how stellar dynamics shape the stellar population near a su- permassive black hole (SMBH), using our galaxy's center as a case study. Focusing on binary disruptions, captures, collisions, and interactions with perturbers, we use numeri- cal simulations to study systems with the SMBH as the central body. We investigate the VHS mechanism observed in hierarchical four-body systems on circular orbits, extend it to relativistic and eccentric cases, and explore its effects on S-stars and disk evolution in the Galactic Center. Our results show that the VHS mechanism is compatible with non-zero eccentricity and demonstrate that disk-like structures can persist or split within the S-cluster. We also investigate the evolution of a disk of binary stars using full N-body simulations, showing that the Hills mechanism can explain hypervelocity stars such as S5-HVS1 originating from the young stellar disk in our Galactic Center. Our results also show that stellar mergers in these disks occur in two separate populations: one closer to the SMBH and below the inner edge of the initial disk, potentially corresponding to the observed dust-embedded objects, and the other farther out. The simulations also naturally reproduce the observed radial trends in binary fractions in our Galactic Center.