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Institut für Astronomie und Astrophysik

Abteilung Astronomie

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Dissertation Marc Patrick Risse

Temporale und spektrale Untersuchungen des Röntgendoppelsternsystems Her X-1/HZ Herculis

30 years passed since the discovery of the X-Ray-Binary Her X-1/HZ Herculis by the satellite UHURU. Meanwhile this object belongs beside Cyg X-1 to the best examined objects of the X-Ray astronomy. But also after so many years of studying these objects there are still numerous questions open, which need to be explained.
The bases of the astronomy are considered first in this work in generally and the X-ray binaries in special (chapter 1). Thereafter I turn to the description of the x-ray binary Her X-1/HZ Her and summarise our present knowledge about this object (chapter 2).
In this work both observations of X-ray satellites and ground-based optical observation data are evaluated. The analysed X-ray data was gathered from the American X-ray satellite RXTE (Rossi X-ray Timing experiment). The optical observation data were made by most different working groups in the whole world in the process of the last 27 years. This huge database from nearly 17000 data points distributed over four spectral bands are analysed under different criteria in this work.
Investigations analysed the pulse shape of HerX-1 using the x-ray data. I determined a deviation of the pulse shape from the well-known mean shape. Detailed investigations showed that the occurrence of this pulse shape is connected with a decrease in the accretion rate (chapter 3).
Furthermore the position of the cyclotron line was tested phase resolved. According to a shift in the cyclotron line energy between 1991 and 1993 by 23 % from 34 to 41 keV Gruber et al (2001), the results could not be compared directly to the older observations. The results derived by Voges et al. (1982) and Soong (1990) could be reproduced (chapter 4).
Using the optical data from HZ Her, the optical companion of Her X-1 the variation of the optical profile was investigated more intense. According to the huge amount of data points the results found by Gerend & Boynton (1976) were improved. In addition I succeeded to develop a model that offers the possibility to forecast Turn-Ons on the basis of current observations (chapter 5).
In the end an existing program source code simulating binary stars was extended by an accretion disc option. The main focus was on the x-ray binary Her X-1/HZ Her and its peculiarities. With this simulation it became possible to describe the main characteristics of the shape of the light curve. It became also possible to describe the movement of the Hot Spots on the surface of the optical counterpart (chapter 6).

Online-Publikation: http://nbn-resolving.de/urn:nbn:de:bsz:21-opus-9106

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