This book fills the gap of a wide scope textbook which is appropriate for first year graduate/final year undergraduate students on active galaxies. This AGN textbook includes phenomena based on new results in the X-Ray domain from new telescopes such as Chandra and XMM Newton not mentioned in any other book. Furthermore, it considers also the Fermi Gamma Ray Space Telescope with its revolutionary advances of unprecedented sensitivity, field of view and all-sky monitoring. Those and other new developments as well as simulations of AGN merging events and formations, enabled through latest super-computing capabilities. The book gives an overview on the current knowledge of the Active Galacitc Nuclei phenomenon. The spectral energy distribution will be discussed, pointing out what can be observed in different wavebands and with different physical models. Furthermore, the authors discuss the AGN with respect to its environment, host galaxy, feedback in galaxy clusters, etc. and finally the cosmological evolution of the AGN phenomenon.
