Stellar Bumper Cars! Collisional Dynamics in Galactic Nuclei with Sanaea Cooper Rose

Like most galaxies, the Milky Way harbors a supermassive black hole (SMBH) at its center, surrounded by a stellar cluster. In this densely populated environment, stars frequently collide and interact with one another. I will discuss the outcomes and implications of these collisions and connect them to astrophysical puzzles observed at the very heart of our galaxy. Close to the SMBH, collisions occur at very high speeds and can produce peculiar stripped stars, divested of their outer layers. However, further from the SMBH, collisions lead to mergers, and successive collisions can produce young-seeming massive stars. Leveraging a semi-analytic model and hydrodynamic simulations, I will describe how collisions shape the mass demographics and orbital properties of the stars. In particular, I will show that collisions can both eject stars from the cluster and place them on nearly radial orbits about the SMBH, such that they wander too close to the SMBH and get pulled apart by tidal forces.

Sponsored by the McDonnell Center for the Space Sciences.