SHAO Astrophysics Colloquia　Towards Imaging the Event Horizon in the Galactic Center　　 

　　Speaker: Heino Falcke（Radboud University Nijmegen）　　 

　　Time: Thursday, 3:00pm, April 2nd　　 

　　Location: Lecture Hall, 3rd floor　　 

　　Abstract:　　 

　　Black holes are theoretical predictions of Einstein’s General Theory of Relativity, where large amounts of matter are concentrated so much that even light cannot escape its gravitational attraction. Thus, black holes mark singularities in space and time, which are surrounded by an event horizon that allows matter and light to go inwards but never go out again. However, do these supermassive black holes and their event horizons really exist? The best place to test this is the center of our own Milky Way. Here a compact radio source with a mass of 4 Million times the mass of the sun, seems to mark the central black hole of our Galaxy, providing by the far the best evidence for the existence of black holes in general. Moreover, its high-frequency radio, near-infrared, and X-ray emission seem to come directly from event horizon scales.  With the help of advanced numerical general relativistic magneto-hydrodynamic simulations emission and appearance of the source can be successfully modeled almost from first principles. Using global mm-wave Very Long Baseline Interferometry (VLBI) experiments – an “Event Horizon Telescope” – it should be possible to even image the elusive event horizon of a black hole for the very first time. All this we address within the framework of a new ERC-funded project, BlackHoleCam, which seeks to turn Sgr A* into a fundamental laboratory for precision black hole astrophysics.　　 

　　Bio:　　 

　　Heino Falcke got his phd in MPIfR in 1992, and then got several positions in MPIfR, University of Maryland, Steward Observatory, University of Boon. He became a full professor of Astroparticle Physics and Radio Astronomy, Radboud University, Nijmegen.　　 

　　His scientific interests include: Radio Emission from Cosmic Rays, low-frequency radio astronomy (LOFAR), radio transients and surveys, SETI, black holes, Galactic Center (Sgr A*), active galactic nuclei (AGN), Seyfert and LINER galaxies, unified schemes of AGN, compact radio cores, radio jets, H2O megamasers, X-ray binaries, accretion disks, high energy emission, compact radio emission in LINERs and LLAGN, proper motions in the local group.