Optical Flash of GRB 990123: Constraints on the Physical Parameters of the Reverse Shock

作     者：Yi-Zhong Fan, Zi-Gao Dai, Yong-Feng Huang and Tan Lu Department of Astronomy, Nanjing University, Nanjing 210093 Yi-Zhong Fan, Zi-Gao Dai, Yong-Feng Huang and Tan Lu Department of Astronomy, Nanjing University, Nanjing 210093

作者机构：Department of Astronomy Nanjing University Nanjing 210093 

出 版 物：《Chinese Journal of Astronomy and Astrophysics》 (中国天文和天体物理学报（英文版）)

年 卷 期：2002年第2卷第5期

页      面：449-453页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：the National Natural Science Foundationof China, the National 973 project (NKBRSF G19990754) the Special Funds for Major State Basic Research Projects the Foundation for the Author of National Excellent Doctoral Dissertation of P. R. China (Project No 

主　　题：gamma rays: bursts   gamma rays: theory 

摘      要：The optical flash accompanying GRB 990123 is believed to be powered by the reverse shock of a thin shell. With the best-fit physical parameters for GRB 990123 and the assumption that the parameters in the optical flash are the same as in the afterglow, we show that: 1) the shell is thick rather than thin, and we have provided the light curve for the thick shell case which coincides with the observation; 2) the theoretical peak flux of the optical flash accounts for only 3×10-4 of the observed. In order to remove this discrepancy, the physical parameters, the electron energy and magnetic ratios, εe and εB, should be 0.61 and 0.39, which are very different from their values for the late afterglow.