摘要
GRB 080913,with a spectroscopically determined redshift of z=6.7,was the record holder for being the most remote stellar object before the discovery of the recent gamma-ray burst GRB 090423,whose redshift is about 8.2.The gradually accumulated high redshift GRB sample has shed light on the origin and physical properties of GRBs during the cosmic re-ionization epoch.Here,we present a detailed numerical fit to the multi-wavelength data of the optical afterglow of GRB 080913 and then constrain its circumburst environment and the other model parameters.We conclude that the late optical/X-ray plateau at about one day since the burst is due to the Poynting-flux dominated injection from the central engine which is very likely a massive spinning black hole with super strong magnetic fields.
GRB 080913,with a spectroscopically determined redshift of z=6.7,was the record holder for being the most remote stellar object before the discovery of the recent gamma-ray burst GRB 090423,whose redshift is about 8.2.The gradually accumulated high redshift GRB sample has shed light on the origin and physical properties of GRBs during the cosmic re-ionization epoch.Here,we present a detailed numerical fit to the multi-wavelength data of the optical afterglow of GRB 080913 and then constrain its circumburst environment and the other model parameters.We conclude that the late optical/X-ray plateau at about one day since the burst is due to the Poynting-flux dominated injection from the central engine which is very likely a massive spinning black hole with super strong magnetic fields.
基金
supported by the National Basic Research Program of China (Grant No. 2009CB824800)
the National Natural Science Foundation of China (Grant Nos. 10473023, 10503012, 10621303, and 10633040)
the Special Foundation for the Authors of National Excellent Doctoral Dissertations of China by Chinese Academy of Sciences,and the NASA Grant (Grant No. NNX08AL40G)
