Fast Spectral Variability in the X-ray Emission of Accreting Black Holes


Book Description

This thesis brings together the various techniques of X-ray spectral analysis in order to examine the properties of black holes that vary in mass by several orders of magnitude. In all these systems it is widely accepted that the X-ray emission is produced by Compton up-scattering of lower energy seed photons in a hot corona or accretion flow, and here these processes are examined through a study of the X-ray spectral variability of each source. A new technique is introduced, in which models are fitted to over 2 million X-ray spectra on time-scales as short as 16 ms, and subsequently it is shown that the nature of the correlation between intensity and spectral index is strongly dependent upon the spectral state of the black hole. Finally, the results of an extensive survey of nearby galactic nuclei using the Chandra X-ray telescope are presented in the form of images and spectra, and these results are used along with data from the literature to search for Compton-thick nuclei.




The X-ray Background


Book Description

A review of the current observational knowledge and understanding of the cosmic X-ray background.







Exploring the X-Ray Universe


Book Description

The one-stop general book on the whole of X-ray astronomy.







Particle Physics and Astrophysics. Current Viewpoints


Book Description

Eight carefully written articles on the interactions between the ideas and concepts of particle physics and those of astrophysics make up this book. Two long introductory lectures give a survey of modern concepts in particle physics and in astrophysics and cosmology, stressing features of common interest. The other six contributions deal with the physics of supernova explosions, with black holes, with neutrino oscillations, with the importance of phase transitions for the large-scale structure of the Universe, and with the use of the ideas of quantum gravity for computer simulations. These rather detailed review articles will be of value for many years to come. The book is intended for graduate students and researchers both in particle physics and in astrophysics.










Literature 1987, Part 2


Book Description

Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysies, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 44 records literature published in 1987 and received before February 15, 1988. Some older documents which we received late and which are not surveyed in earlier volumes are inc1uded too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. Dr. Siegfried Böhme retired from his duties as co-editor of Astronomy and Astro physics Abstracts on December 31, 1987. Since 1950 he partieipated in the biblio graphie work of the institute. He served as a reviewer for the Astronomischer Jahresbericht and became one of the editors of Astronomy and Astrophysics Ab stracts in 1969. After his retirement in 1975 he took care of, particularly, the Russian literature on a voluntary basis for 12 years. It is a pleasure to thank Siegfried Böhme for his valuable contributions. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Christiane Jehn, Ms. Monika Kohl, Ms.




Symposium


Book Description