Central Engine of Long GRBs, Propagation of Relativistic Jets, and Emission Mechanism of GRBs.----中国科学院紫金山天文台

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)

Abstract　　　

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).