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TAPIR Seminar

Friday, February 10, 2023
2:00pm to 3:00pm
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Online and In-Person Event
Collisions in Galactic Nuclei: Stars, Binaries, and Black Holes
Sanaea Rose, Graduate Student, Astronomy & Astrophysics, UCLA,

In person: 370 Cahill -- Attendees joining in person must have a valid Caltech UID.

To Join via Zoom: 864 8902 5566

ABSTRACT: Like most galaxies, the Milky Way harbors a supermassive black hole (SMBH) at its center. Surrounding the SMBH is a dense cluster of stars and stellar remnants. In this cluster, objects frequently collide and interact with one another. I will discuss how this environment leads to unique populations of stars and stellar remnants. While stars often reside in binary configurations, the dense environment in a galactic nucleus works to destroy these systems. An observed stellar binary can therefore place constraints on the density of objects in its neighborhood, including the number of compact objects there. Generally challenging to detect, these compact objects are also affected by collisions with surrounding stars. Most stellar evolution models predict that black holes (BHs) cannot form above a certain mass. However, over many collisions, a stellar-mass BH can grow appreciably in size. Our results suggest that BHs above the maximum mass predicted by stellar evolution models may be ubiquitous in galactic centers. Lastly, I will comment on the role of stellar collisions in shaping the broader stellar population, for example, by creating more massive, rejuvenated stars.

For more information, please contact JoAnn Boyd by phone at 626-395-4280 or by email at [email protected].