Binaries in the Grip of Sgr A*: Recaptures, Ejections and Mergers Across Multiple Encounters
Young stars (S stars) and G objects orbit around SgrA*, while a population of stars is ejected from the Galactic Centre (GC) at very high speeds (Hypervelocity stars - HVSs). Understanding these systems provides information on how the GC is populated and on the origin and assembly history of SgrA*.
A common explanation of the dynamical origin of these systems is the tidal encounter between stellar binaries and supermassive black holes (MBHs) through the Hills mechanism; a binary can disrupt (dissolving into an HVS and an S-star), merge (possibly resulting into a G object) or survive the interaction. The letter may come back to interact again with the MBH.
In this talk, I will present my novel approach to accurately follow the evolution of an initial population of binaries through multiple subsequent encounters. I will describe third-generation HVSs, characterise S-stars, and, for the first time, ejected binaries. I will also discuss the fraction of systems that merge.
Finally, I will briefly focus on another possible interesting outcome of the Hills mechanism: extreme mass ratio inspirals.
[Host: Alberto Sesana]