Uncovering the Galactic Black Hole Population with Gravitational Microlensing

There are expected to be 100 million black holes (BHs) in the Milky Way, although until recently mass measurements existed for only two dozen or so in X-ray binary systems. However, a substantial fraction of the Milky Way's BHs are expected to be isolated. Only by detecting these isolated BHs can we characterize the full Galactic BH population and understand their formation. In this talk I will discuss the search for isolated BHs via gravitational microlensing. I will first present recent progress on this question, then discuss Roman's potential to be a BH finding machine.

Speaker: Casey Lam (Berkeley)

The Roman Lecture Series is a monthly virtual lecture series focused on the scientific capabilities and technology of the Nancy Grace Roman Space Telescope, organized by Roman Mission partners.