Author: Nissim Illich Fraija Cabrera
Abstract: Delayed photons with energies greater than 100 MeV have been detected in a few gamma-ray bursts (GRBs). The emission of these photons can be either, of longer or shorter duration than duration of the prompt emission. We propose that long- and short- lasting emissions can be understood as synchrotron self-Compton (SSC) emission in the thick case from the reverse and forward external shocks, respectively, when the jet is magnetized. We have tested the model in several bursts as GRB090926 and GRB980923 and found fluxes, energies and durations of the emissions consistent with the observations. We have found that the presence of a short-duration high-energy emission can be interpreted as a consequence of magnetized jet, while the longer duration emission may be an indication of the external environment density. Here, we present the model and results for several bursts.