%0 Journal Article
%T Black holes in Active Galactic Nuclei: observations
%A Greg M. Madejski
%J Physics
%D 1999
%I arXiv
%X This paper summarizes the observations which provide the best evidence for the presence of black holes in active galactic nuclei. This includes: X-ray variability; kinematical studies using optical emission lines as well as the distribution of megamaser spots; and the shape of the Fe K$\alpha$ X-ray emission line. It also presents the current status of our understanding of jet-dominated active galaxies (blazars), and briefly reviews the currently popular AGN ``Unification Schemes.''
%U http://arxiv.org/abs/astro-ph/9903141v1