Supermassive Black Holes in Galaxies

Chandra and XMM detect X-rays emitted during accretion onto supermassive black holes, even when they are highly obscured. I review what has been learned about the cosmic evolution of the X-ray luminosity functions and the reconstruction of the accretion history of supermassive black holes from extensive follow-up observations of both deep and wide-area Chandra X-ray surveys.