Seminar Title:	Central Engine of Long GRBs, Propagation of Relativistic Jets, and Emission Mechanism of GRBs
Speaker:	Prof. Shigehiro Nagataki
Affiliation:	(Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho Kitashirakawa Sakyo-ku, Kyoto 606-8502, Japan)
When:	Tuesday Morning, Aug. 8th, 10:00 a.m
Where:	Room 202, Astronomical building, Astronomy Department of Nanjing University.
	Welcome to Attend
	( PMO Academic Committee & Academic Circulating committee)

　

　 Absaugtract　

I would like to present our current status on "Numerical Simulations of Collapsars". I would like to show the simulations of the central engine of Long Gamma-Ray Bursts by the General Relativistic MHD code (Nagataki ApJ 2009). Especially, I would like to show that a strong jet is launched from a rapidly rotating black hole. I would like to show how the jet is collimated, which determines the opening angle of the jet (Nagataki PASJ 2010). Also, I would like to show the simulations of propagation of a relativistic GRB jet and thermal emission from its photosphere, which may be related GRB090902B that showed a clear two-component spectrum (Mizuta, Nagataki, Aoi ApJ 2011).