AR 14571 (Archival Research)

Thu Jul 18 13:53:29 GMT 2024

Principal Investigator: Noe Kains
PI Institution: Barnard College
Investigators (xml)

Title: Searching for an intermediate-mass black hole in M 22 with gravitational microlensing
Cycle: 24

We propose to analyze archival data spanning over 20 years to search for astrometric shifts caused by microlensing of background stars by an intermediate-mass black hole (IMBH) in the core of globular cluster M 22. The detection of such a shift would allow us to make the first unambiguous detection of an IMBH, and to constrain its mass, providing us with valuable insight into the formation of supermassive black holes (SMBH) and galaxy evolution. Non-detections of lensing events, coupled with our simulations, would also allow us to place strong constraints on the presence of an IMBH in M 22, which would be particularly interesting in light of the detection of stellar-mass black holes in this cluster (Strader et al. 2012). The main science product of the archival work, long-baseline astrometric measurements of thousands of cluster and Bulge stars, will also be very useful for stellar population studies, allowing for the study of the rotation of the multiple populations in M 22.