Astro Seminar
Stellar Clusters as the Nurseries of Black Holes
Speaker: Sebastian Kamann (LJMU)
Date: Wednesday 1 December 2021
Time: 14:00
Venue: Zoom
Over the last years, the continuous discovery of gravitiational waves from merging black holes has resulted in a quantum leap of our understanding of the most enigmatic objects in the Universe. Still, many open questions remain. In my talk, I will highlight the importance of star clusters in our quest of performing a cosmic census of black holes. Being the natural habitat of massive stars, star clusters are expected to form numerous black holes as their stellar populations age. However, the fate of a clusters' black hole population is still largely unknown. It is expected that many black holes are ejected from the clusters following natal kicks they receive during supernova explosions. Others will remain inside the clusters and interact, resulting in binary black hole mergers and potentially the growths of intermediate-mass black holes with masses above 100x solar. I will describe how integral-field spectroscopy has opened a new window to uncover the hidden black hole populations of star clusters. In particular, I will show results from an ongoing MUSE survey of massive star clusters, which has already lead to the detection of several black holes in the Galactic globular cluster NGC3201. I will show how such observations, in combination with sophisticated dynamical models, allow us to constrain the numbers and masses of black holes residing in star clusters of all ages.