Disk-Corona Models and X-ray Emission from Seyfert Galaxies
Loading...
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
The current status of understanding of the X-ray emission from Seyfert galaxies involves Comptonization of soft photons by hot subrelativistic electrons. After briefly reviewing the early theoretical basis for the presence of hot optically thin plasma in or around accretion disks and the key observations that led to develop the presently popular model of an accretion disk with a hot corona, we summarize recent progress in accretion models that take into account energy dissipation and/or angular momentum transport in the corona. Finally, adopting the simple scheme of a homogeneous plane parallel corona, we discuss in detail the dependence of the X-ray spectrum on the coronal parameters. Despite the strong coupling between optical depth and temperature which determines a spectral shape insensitive to their precise values, moderate spectral changes are possible. The spectral variability patterns can be used as diagnostics for coronal physics and should allow to determine whether the optical depth of the corona is dominated by e+e- pairs.
13 pages, AAS latex [11pt,paspconf,epsf], + 4 .eps figures To appear in the Proceedings of the 163 IAU conference. Also available at http://fy.chalmers.se/~haardt/personal/curr.html
13 pages, AAS latex [11pt,paspconf,epsf], + 4 .eps figures To appear in the Proceedings of the 163 IAU conference. Also available at http://fy.chalmers.se/~haardt/personal/curr.html