Speaker: Dr. J M Stone

Host: Matthew Liska

Title: Modeling Luminous Black Hole Accretion Flows

Abstract: A variety of new results from general relativistic MHD models of black hole accretion flows in luminous systems (such as quasars and X-ray binaries) that include full radiation transport will be described. The models allow observationally important quantities
such as the radiative efficiency, variability, and kinetic feedback in winds to be measured over a range of luminosities, from sub-Eddington to highly super-Eddington.  An important question is how luminous black holes are fed from their surroundings, which requires modeling the accretion flow over many orders of magnitude in radial scale.  New results regarding the formation of cold chaotic accretion flows onto the central black hole in elliptical galaxies such as M87 from kiloparsec down to near horizon scales will be presented, and a new "cyclic zoom" method that enables evolving such flows over cosmic time scales will be introduced.

Bio: A professor of astrophysics at the Institute for Advanced Study in Princeton, NJ.  His research focuses on nonlinear fluid dynamics in astrophysical systems, such as turbulence in the interstellar medium and accretion flows onto black holes.  He is a key developer of numerical codes for astrophysical simulations, like the Zeus and Athena codes