Gamma‐ray burst efficiency and possible physical processes shaping the early afterglow

  title={Gamma‐ray burst efficiency and possible physical processes shaping the early afterglow},
  author={Yi-zhong Fan and Tsvi Piran},
  journal={Monthly Notices of the Royal Astronomical Society},
The discovery by Swift that a good fraction of gamma-ray bursts (GRBs) have a slowly decaying X-ray afterglow phase led to the suggestion that energy injection into the blast wave takes place several hundred seconds after the burst. This implies that right after the burst the kinetic energy of the blast wave was very low and in turn the efficiency of production of gamma-rays during the burst was extremely high, rendering the internal shocks model unlikely. We re-examine the estimates of kinetic… Expand

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