Multiwavelength Surveys for Active Galactic Nuclei - 2019 October (Out-of-Date - See Notes)

Note that this old lecture has been superseded by    • An Observational Overview of Active Galact...   which is updated, improved, and better organized - specifically, see Lecture #2 of that Playlist. This is a recording of a talk titled "Multiwavelength Surveys for Active Galactic Nuclei" prepared for IAU Symposium 356, "Nuclear Activity in Galaxies Across Cosmic Time" (2019 Oct 7-11; Addis Ababa, Ethiopia). The talk here was recorded separately, and is longer and more detailed since I did not have the time constraint I had in Ethiopia. The speaker is Prof. W.N. Brandt from the Department of Astronomy & Astrophysics at the Pennsylvania State University. As noted in the talk itself, this represents a broad review of an enormous field of endeavor. It aims just to cover some of the main ideas, while keeping the coverage accessible for students. My apologies in advance if your favorite research is not covered. At the end of the talk, I give references to several useful recent review papers that can help interested people delve further into the extensive literature. Here is the talk abstract: Most of what we know about active galactic nuclei (AGNs) has been driven, or at least strongly shaped, by our methods for finding them, and multiwavelength AGN surveys have achieved remarkable successes in recent decades. I will present a broad, and thus necessarily shallow, review of such multiwavelength AGN surveys. I will first present some brief introductory points on, e.g., general survey approaches, AGN luminosities, host galaxies, and anisotropic emission/obscuration. I will then review many of the key current surveys and their results, separating these into ground-based and space-based surveys. Finally, I will discuss some future prospects including essential remaining questions and "discovery space" considerations.