The Formation and Growth of Black Holes in the Universe: New cosmological clues

<!--HTML-->In the last few years a change of paradigm occurred in the field of black hole research. We now believe, that stellar mass black holes are created in powerful gamma ray bursts. Stellar remnants of the first generation of stars have very likely been the seeds of supermassive black holes, which we find dormant in the centers of most nearby galaxies - including our own Milky Way. A tight correlation between black hole mass and the global properties of their host galaxies indicates a co-formation and evolution of black holes and galaxies. The X-ray sky is dominated by a diffuse extragalactic background radiation, which our team, together with others, was able to resolve almost completely into discrete sources using the X-ray satellites ROSAT, Chandra and XMM-Newton. Optical and NIR follow-up identifications showed, that we observe the growth phase of the population of supermassive black holes throughout the history of the Universe. The accretion history derived from X-ray observations shows, that the black holes have been formed together or even before the bulk of the stars in galaxies. Major mergers between two galaxies seem to play an important role in the feeding of black holes. In a nearby merger event we could identify a double supermassive black hole in a single galaxy for the first time, which will merge in the future. In addition, we discovered several normal galaxies, in which an otherwise dormant black hole disrupts and swallows a normal star, which came too close. In this seminar I try to put these findings into a closed scenario about the formation and evolution of black holes. In addition I will discuss the roles and discovery potential of the proposed X-ray observatories DUO, ROSITA and XEUS.<BR><BR><I>Organiser(s): Rolf Landua / PH-EP Unit</I><BR><BR><I>Note: Tea and coffee will be served at 16.00 hrs</I>