SIMBAD references

Recent observations on the gamma-ray burst (GRB) 000301c afterglow show that one sharp break appears in the global optical/IR light curves, and in particular the decay slope at late times is as steep as about -3.0. This unusual feature is clearly inconsistent with the standard afterglow shock model. Here we propose a non-standard model for the afterglow of GRB 000301c, in which an initial ultra-relativistic shock in a dense medium (``dirty environment'') rapidly evolved to the non-relativistic phase in 1 day after the burst. During such a phase, the shock was refreshed by a strongly magnetized millisecond pulsar through magnetic dipole radiation. This refreshment led to flattening of the light curves. After the energy injection, the afterglow decayed as ∝t^–3.0 if the electron distribution index of the shocked medium, p≃3.4, derived from the optical spectrum. Therefore, our model can provide a plausible explanation for the peculiar optical/IR afterglow light curves of GRB 000301c.