12. Dec. 2013, 16:15 Uhr, Gebäude NW1, Raum H3
The Galactic Center Black Hole - Approaching the Event Horizon
Prof. Frank Eisenhauer , MPI for extra-terrestrial Physics, Garching
Infrared observations of stellar orbits and the extreme compactness of the central radio source provide compelling evidence that the Galactic Center harbors a supermassive black hole. Given its relative proximity, the Galactic Center is the ideal laboratory for studying the details of such an extreme object. Currently we are witnessing a special event, a gas cloud on its way towards the supermassive black hole. Following an almost radial orbit, its dynamic evolution will shed light on the feeding processes and probe the properties of the accretion flow. Soon infrared and submillimeter interferometry will take the next steps in the Galactic Center research by providing event-horizon scale astrometry and imaging resolution. While the submillimeter interferometry aims at imaging the shadow of the black hole against the surrounding accretion flow, the infrared interferometry with GRAVITY - a new instrument combining the four 8m ESO Very Large Telescopes in Chile - will focus on measuring the motion of matter close to the last stable orbit and on detecting general relativistic effects in the stellar orbits at larger distance. The presentation will cover both the experimental and astrophysical aspects of this project.