Flat spectrum gamma ray burst afterglows

Abstract

Temporal behaviour of GRB afterglow light curve is derived for the case where the electron energy distribution is relatively hard, with the power-law index p lying between 1.0 and 2.0. It is shown that the expected behaviour will be the same as that for p > 2.0 if the upper cutoff in the electron energy distribution evolves in direct proportion to the bulk Lorentz factor of the blast wave.