Abstract

Invited Talk - Plenary

Tuesday, 08 September 2026, 11:30   (MW-1801 / virtual plenum)

oMEGACat and the intermediate-mass black hole in Omega Centauri

Maximilian Häberle
European Southern Observatory

The massive globular cluster Omega Centauri is likely the stripped nucleus of an accreted dwarf galaxy and, therefore, provides a unique opportunity to study the central region of a galaxy whose evolution halted billions of years ago. In recent years, we have created oMEGACat, the largest astrometric and spectroscopic dataset for any star cluster, with the goal of deciphering both the formation history and the dynamics of Omega Centauri. I will give an overview of this project and then focus on the exciting discovery of several fast-moving stars in the very center of the cluster. These stars provide potentially the best evidence for an intermediate-mass black hole (IMBH) we have to date. These elusive IMBHs have masses between stellar-mass black holes and supermassive black holes, providing a missing link in our understanding of how supermassive black holes form.