Einladung zum Promotionsvortrag von Herrn Tobias Beuchert:
„Multiwavelength Observations of Active Galactic Nuclei from the Radio to the Hard X-Rays“
Active Galaxies form a peculiar type of galaxies. Their cores, the so-called “Active Galactic Nuclei” (AGN), are the most persistent luminous objects in the universe. Accretion of several solar masses per year onto black holes of Billions of solar masses drive the immense energy output of these systems, which can exceed that of the entire galaxy. The compact energy source, however, only measures about one over a Billion times that of the entire galaxy. Subject of my thesis are observations of the two main channels of energy release of selected AGN systems, both of which are encompassed by profound and yet unanswered questions. These channels are the pronounced X-ray emission of the hot and compact accreting environment in close vicinity of the black hole and the radio synchrotron emission of magnetically collimated jets that are fed by portions of the accreted matter and accelerate the same deep into the intergalactic medium. As the circumnuclear environment of AGN is too compact to be spatially resolved in the X-rays, I show how X-ray spectroscopy can be used to: (1) understand the effects of strong gravity to trace the geometry and physics of the X-ray source and (2) more consistently quantify matter that surrounds and dynamically absorbs our direct line of sight towards the X-ray source. Second, I unveil the valuable information contained in the polarized radio light being emitted from magnetized jets. In contrast to the X-ray emitting region, I am able to spatially resolve the inner parts of the jet of a prominent galaxy with help of a network of radio telescopes that are separated across Northern America. The resulting polarization maps turn out to be exceptionally promising in answering fundamental questions related to jet physics. (Vortrag auf Englisch)
Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.