Joint Astrophysical Colloquium
Black Hole Formation and Demography in the Milky Way
Poshak Gandhi (University of Southampton)
Thursday 23/05/2024 @ 11:30, Sala Antonio Sollima (IV piano Battiferro)
Recent years have witnessed the discovery of new populations of stellar-mass black holes in the Galaxy. We now have dynamical mass confirmation of about two dozen black holes in X-ray binaries, and are beginning to uncover the first non-accreting systems from astrometric, microlensing and blind spectroscopic surveys. Astrometry also provides powerful geometric constraints on the distances, kinematics and system properties of compact object binaries, which can be used to shed light on their formation mechanisms, in particular the strengths of their progenitor supernova natal kicks. Such kicks provide a key constraint on merger rates of gravitational wave sources. While binary evolution can explain the current properties of X-ray binaries, some of the newer wide binaries present a deep evolutionary puzzle. I will review our knowledge of black holes demography and formation mechanisms in the Galaxy, and outline expectations in upcoming surveys within this decade. I will end by proposing new avenues for next-generation astrometric missions, and on taking the leap to search for supermassive black holes kicks in external galactic nuclei.