Universe Colloquium: Fatal fate: A gas cloud cloud on its way to the massive black hole in the Galactic Center

by Stefan Gillessen (MPE)

Wednesday 8 Oct 2014, 16:30 → 17:30 Europe/Berlin

seminar room (Excellence Cluster Universe, Boltzmannstrasse 2, Garching)

The Galactic Center is a unique astrophysical laboratory. Due to its proximity, we can observe in unparalleled detail the interaction of the massive black hole with its stellar and gaseous environment. In 2011, we discovered a compact gas cloud (”G2”) with roughly 3 Earth masses that is falling on a near-radial orbit toward the massive black hole, with a pericenter passage in 2014. Our 10-year data set beautifully shows that G2 gets tidally sheared apart due to the massive black hole’s force. We expect that in addition to the tidal effects, hydrodynamics will get important in the coming years, as G2 collides with the hot ambient gas around Sgr A*. Simulations show that ultimately, the cloud’s material will fall into the massive black hole. Predictions for the accretion rate and luminosity evolution, however, are very difficult due to the many unknowns. Nevertheless, this might be a unique opportunity in the next years to observe how gas feeds a massive black hole in a galactic nucleus. The Universe Colloquium is followed by a social gathering with wine and cheese.