The search for massive stars with black-hole companions
Speaker: Soetkin Janssens (RESCEU, U. Tokyo)
Abstract:
Massive stars play an important role in the evolution of galaxies. With masses larger than eight times the mass of the Sun, these stars regulate galaxy-wide feedback and star formation. They end their lives with a violent supernova, leaving behind a compact object — neutron star of black hole. The formation of black holes is however insufficiently understood, largely due to a limited number observations. While over ten million black holes are predicted to reside in the Milky Way, only very few have been discovered so far. Moreover, in the past years, several black-hole imposters were discovered, highlighting the difficulty of the black-hole search. However, this search is far from over and the coming years may be very promising. While our current methods are very slowly becoming fruitful, a new method is on the way that may uncover hundreds of black holes at once based on astrometric data from the Gaia space telescope. This will reveal how black holes form and will help us to better understand the evolution towards gravitational wave mergers.