Institute for Advanced Study/Princeton University Joint Astrophysics Colloquium

The study of powerful, highly obscured accreting black holes has recently seen dramatic advances with hard X-ray observations from NuSTAR and mid-infrared data from WISE. These "hidden" obscured quasars were for a long time elusive, but we can now identify millions of these objects across most the sky, and characterize the nature of their obscuration and their role in the formation of galaxies. I will describe a few recent efforts to characterize the star formation rates, dark matter halo masses, and level of obscuration in these "hidden" AGN, and present evidence that (at least some) powerful obscured quasars represent an evolutionary phase in the evolution of their host galaxies, as predicted by models of galaxy formation.