Not all of the matter which comes under a black hole's influence ends up inside, because accretion of just a small amount releases enough energy to expel a much larger amount. These outflows carry a lot of energy and profoundly affect the black hole's environment, as demonstrated by recent X-ray and radio observations showing that cooling flows - gas thought to be cooling and slumping into the centers of clusters - can be stopped completely by the outpouring energy.
This project will study the details of this influence, exerted not by outbursts but through a milder process called "effervescent heating", on the X-ray-emitting atmospheres of galaxy clusters, and on the growth of supermassive black holes at high redshift. The investigators will study the physical basis of effervescent heating and its implications through analytic modeling and state-of-the-art numerical simulations. They will research whether the tight coupling between galaxies and the formation of their central black holes arises from feedback via the released energy, and achieve new understanding of how the formation and evolution of super-massive black holes is linked to the formation and evolution of galaxies and galaxy clusters.
The research will promote undergraduate science education and help with the general public's understanding of scientific research, because black holes have a widespread fascination which makes them an excellent "hook". The PI will also maintain his contacts with science journalists and popular magazines, continue with his own writings, and use his research results in his generally available courses.
