Study and modeling of High Energy Emission from Gamma Ray Bursts
José Rodrigo Sacahui Reyes
INPE
Gamma Ray Bursts (GRBs) are short and intense gamma ray emissions. Some GRBs clearly present a distinct High-Energy (HE) component that evolves independent of the usual Band function. These components are both, long and short lasting compared to the burst duration. Most of the models only explain the long duration HE component. Here, I will present the discovery of the first short duration HE compoent and a leptonic model on the external shock framework to describe both long and short lasting HE component. This model already had been proven in GRB980923 and GRB090926A, the first one with a short duration component and the second one with both long and short HE component. We apply the model to Other bursts with encouraging results. We propose that the HE component is composed by two emissions, one of short duration that falls in the MeV regime and in coincidence with the prompt phase, and the second long lasting emission that emits GeV photons. Both could be understood as SSC emission from the reverse and forward shock respectively. This model requires a magnetized jet and a reverse shock in the thick shell case. All fluxes, energies and durations are consistent with the observed values.