New Insights into the Cosmic Growth of Supermassive Black Holes

Using a "wedding cake" combination of multi-wavelength X-ray+infrared+optical surveys, we measure the growth of supermassive black holes at the centers of galaxies over the ~12 billion years. Most actively growing black holes ("Active Galactic Nuclei" or AGN) are heavily obscured and thus look like inactive galaxies in optical surveys, so our census has effectively quadrupled the amount of accretion, and thus the amount of energy deposited in AGN host galaxies. However, contrary to leading models, our data suggest that for only a minority of galaxies does merger-triggered AGN "feedback" cause rapid quenching of star formation. 

Speaker: Meg Urry, Yale Univ.