Roman Virtual Lecture

Jul. 15, 2021

Speaker (Affiliation):
Kailash Sahu (STScI)

Detecting Stellar-Mass Black Holes through Astrometric Microlensing and Transits


About 100 million black holes are estimated to exist in our Galaxy, a large fraction of which are expected to be isolated. Yet, not a single isolated black hole has been detected to date – all of the few dozen black holes detected so far are in binaries. Astrometric Microlensing is the only available technique capable of detecting isolated black holes and measuring their masses. Roman Telescope's high angular resolution and wide field of view offer an ideal combination to detect isolated black holes and measure their masses. Roman will continuously monitor the rich stellar fields of the Galactic bulge for several months repeatedly, which will be used to discover planets through their transit signals. I will show that these observations can also be used to discover white dwarfs, neutron stars and black holes through their microlensing signals during transits.