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Wednesday, January 3, 2024
4:00pm to 5:00pm
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Cahill, Hameetman Auditorium
Black Holes and Revelations: Unseen Companions in Stellar Binaries
Kareem El-Badry, Assistant Professor of Astronomy, California Institute of Technology,

The Milky Way contains of order 10^8 stellar-mass black holes (BHs). Yet, fewer than 100 BH candidates are known, and only about 20 are dynamically confirmed. Our view of the BH population has been shaped almost entirely by observations of X-ray binaries and gravitational wave sources, both of which represent an extremely rare outcome of binary evolution. I will discuss recent efforts to uncover the (potentially) much larger population of Galactic black holes in non-interacting binaries, focusing both on interpretation of confirmed dormant BHs and on what can be learned about binary evolution from the menagerie of interacting binaries and stripped stars that have masqueraded as dormant BH binaries. Finally, I will discuss our emerging view of the BH mass distribution from observations of X-ray binaries, dormant BH binaries, BHs detected via photometric and astrometric microlensing, and BHs in gravitational wave events. 

For more information, please contact Jim Fuller by email at [email protected] or visit