Is GRB 050904 a Superlong Burst?

Abstract

By considering synchrotron radiative process in the internal shock model and assuming that all internal shocks are nearly equally energetic, we analyze the gamma-ray burst (GRB) emission at different radii corresponding to different observed times. We apply this model to GRB 050904 and find that our analytical results can provide a natural explanation for the multiband observations of GRB 050904. This suggests that the X-ray flare emission and the optical emission of this burst could have originated from internal shocks due to collisions among nearly equally energetic shells ejected from the central engine. Thus, GRB 050904 appears to be a burst with superlong central engine activity. © 2006. The American Astronomical Society. All rights reserved.