Abstract: Although AGN unification model is very successful to explain many observational properties of AGN, little progress has been made to understand the physical properties of the inner accretion disks, where most of the photons are emitted.The standard thin disk model, which has been widely used to model the accretion disks, causes a lot of puzzles for AGN disks theoretically and cannot easily explain recent micro-lensing observations and timing analysis of quasars.I will first point out that the iron opacity bump can significant change the structures and properties of AGN accretion disks compared to case with dominated electron scattering opacity. Then I will show a series of global 3D radiation MHD simulations of AGNs for a wide range of accretion rates, particularly the importance of density waves for angular momentum transfer and strong outflows from the disks driven by the strong opacity peaks. I will also discuss implications of these simulations for understanding AGNs and their interactions with the host galaxies.

 

Bio: Prof. Yanfei is currently a KITP fellow at the Kavli Institute of Theoretical Physics in University of California, Santa Barbara. He got his Ph.D. in August, 2013 from the Department of Astrophysical Sciences of Princeton University. Prof. Yanfei is working on several projects where radiative transfer plays an important role. His main research tool is numerical simulation, which uses the most advanced numerical algorithms.  But he is also interested in observations to help him think about the problems from a completely different point of view.