Dr. Rosalba Perna -- The Neighborhood of a Supermassive Black Hole

Planets orbit stars, and moons orbit planets, so what orbits a supermassive black hole? Possibly a whole lot of stuff, including a gaseous disk, thousands of stars and more "normal size" black holes! Dr. Rosalba Perna tells us about all the crazy things that could be orbiting around the supermassive black holes that we detect at the center of active galaxies.