Astronomy Colloquium / Fall 2008

September 17

Prof. Omer Blaes

University of California Santa Barbara

How Does Accretion Onto Black Holes Really Produce the Light We Observe in Quasars and X-ray Binaries?

Just as you can build an equilibrium model of a star without knowing anything about nuclear reactions, building an equilibrium model of an optically thick accretion disk around a black hole can be done without knowing anything about the turbulence that is responsible for liberating accretion power. But if you want to predict evolution (variability!) or even observed spectra, you have to do more. Thanks to supercomputer simulations of MHD turbulence, accretion disk theory is now undergoing a revolution that is comparable to the revolution in our understanding of how nuclear reactions determine stellar evolution. I will describe some of the recent progress, focusing in particular on what we have learned about luminous accretion disks (with photons!) around black holes.