EXTREME PHYSICS AROUND BLACK HOLES: UNDERSTANDING ACCRETION-DISK PHYSICS AT THE EDGE OF THE BLACK-HOLE EVENT HORIZON

Black holes in our Galaxy have masses between 5 and 15 times that of our Sun, and are formed when a massive star explodes in a Supernova. A black hole is so massive and confined in such a small volume in space, that not even light can escape its gravitational attraction. Fortunately, some black holes are in binary systems with a star similar to, or smaller than our Sun. If the black hole and the companion star are close enough, the strong gravity produced by the black hole will slowly "suck" gas from its companion, deforming it into a pear-shape star. The gas pulled off by the black hole does not fall directly into it, but swirls in like bath water around a plug-hole, forming a disk of gas which astronomers call accretion disk.

What are the fundamental physics that rule accretion disks? What are the physical ingredients needed to produce ultra-fast winds and jets? The PhD student will join the group of high-energy astrophysics in order to tackle some of the most fundamental questions of accretion disk physics. To do so, the student will use high-time resolution data from NASA's newest X-ray instrument "Neutron star Interior Composition Explorer", in combination with data from state-of-the-art optical, infrared and Radio facilities.