Diverse manifestations of violent activity in the nuclei of galaxies are believed to result from the interactions of matter with a supermassive black hole. However, the details of these interactions and their observational signatures are not well understood. This award will support theoretical research studying three important classes of phenomena in active galactic nuclei (AGNs): the formation of relativistic jets, the production of X-ray spectra, and interactions involving ultrarelativistic particles. The investigations described in this proposal will address the questions: Why do some AGNs produce powerful jets while others do not? What can X-ray observations tell us about the temperatures, densities, and spatial organization of matter close to the black hole? What roles (if any) do ultrarelativistic particles play in shaping the energy output of an AGN, and how does this energy affect the environment of the AGN? The long-term goals of this research are: 1) to determine whether the interactions of matter with a supermassive black hole really are responsible for AGN phenomena; 2) to understand in detail how these interactions take place: and 3) to learn what effects nuclear activity can have on the appearance and evolution of the host galaxy.
