Event Horizon Telescope recently produced the first resolved image of a putative black hole.  The observed ring-like structure is believed to be produced by a hot, luminous, translucent gas that circulates around a black hole, with the form of the image strongly modified by gravitational lensing. I will describe a program of modeling the black hole image that relies on ideal and non-ideal relativistic fluid simulations coupled to polarized relativistic radiative transport.  I will show that the observed image is broadly consistent with these state-of-the-art models, and describe future opportunities for measuring black hole spin and testing for the extraction of black hole spin energy via a Penrose-like process.

Charles Gammie is a Professor of Physics and of Astronomy at the University of Illinois at Urbana-Champaign.  He is interested in theoretical and computational astrophysics and especially in problems related to black hole accretion, planet formation, star formation, interstellar turbulence, and the outcome of planetary-scale collisions.