The synchrotron-self-Compton radiation accompanying shallow decaying X-ray afterglow: the case of GRB 940217

Abstract

High energy emission (> tens MeV) of Gamma-Ray Bursts (GRBs) provides an important clue to understand the physical processes involved in GRBs, which may be correlated with the GRB early afterglow. A shallow decline phase has been well detected in about half {\it Swift} Gamma-ray Burst X-ray afterglows. The widely considered interpretation involves a significant energy injection and possibly time-evolving shock parameter(s). This work we calculate the synchrotron-self-Compton (SSC) radiation of such an external forward shock and show that it could explain the well-known long term high energy (i.e., tens MeV to GeV) afterglow of GRB 940217. We propose that the cooperation of Swift and GLAST will help to reveal the nature of GRBs.

11 pages, including 1 figure and 1 table