X-ray Survey Results on Active Galaxy Physics and Evolution
  This "pedagogical" review describes the key Chandra and XMM-Newton extragalactic surveys to date and details some of their implications for AGN physics and evolution. We additionally highlight two topics of current widespread interest: (1) X-ray constraints on the AGN content of luminous submillimeter galaxies, and (2) the demography and physics of high-redshift (z > 4) AGN as revealed by X-ray observations. Finally, we discuss prospects for future X-ray surveys with Chandra, XMM-Newton, and upcoming missions. 
W.N. Brandt (Penn State), D.M. Alexander (Cambridge IoA), F.E. Bauer   (Cambridge IoA), and C. Vignali (Oss. Ast. Bologna)