2003/06/02 by Y. Z. Fan, Z. G. Dai, Y. F. Huang +1
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1088/1009-9271/2/5/449
published as Chin.J.Astron.Astrophys.2:449,2002 · 7 pages, no figure
arxiv created 2003/06/02 · arxiv updated 2014/10/13
The optical flash accompanying GRB 990123 is believed to be powered by the reverse shock of a thin shell. With the best fitted physical parameters for GRB 990123 (Panaitescu & Kumar 2001) and the assumption that the parameters in the optical flash are the same as those in the afterglow, we show that: 1) the shell is thick but not 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 compensate this divergency, the physical parameters the electron energy ration and the magnetic ratio εe, εB should be 0.61, 0.39 respectively, which are much different from those in the late afterglow.