Einladung zum Promotionsvortrag von Frau Maria Hirsch:
„Roentgenbeobachtungen Schwarzer Loecher / X-ray Observations of Black Holes“
Although a variety of black hole binaries is known and well observed in the X-ray regime, these systems still pose open questions and manage to puzzle the observer with their behavior. I will highlight two of these systems, GRS 1758-258 and Cygnus X-1, to illustrate different aspects of physics near black holes.
The intermediate mass X-ray binary GRS 1758-258 is a persistent source located in the Galactic ridge. Whereas other systems of this class follow the canonical pattern of state changes, GRS 1758-258 showed an irregular soft/off state for the second time in 2016. I present INTEGRAL and Swift Target of Opportunity observations of this soft/off state.
Whereas the source became invisible in the hard X-rays, a blackbody disk component can be seen to emerge in the soft X-rays in the course of the state change.
Cygnus X-1 is one of the best studied wind accreting high mass X-ray binaries. Its soft X-ray light curve shows strong dips where clumps in the highly photoionized, focused wind of the donor star HDE 226868 pass our line of sight. Chandra HETGS observations allow for an investigation of the wind’s properties. I discuss the evolution of Si and S K alpha spectra with four different dipping stages. The distribution of ionization stages during the dip points towards a complex ionization structure of the wind material. (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.