Detecting high energy photons from gamma ray bursts

Abstract

Within the internal shock scenario the photon spectra from a Gamma Ray Burst (GRB) is dominated by the leptonic component. The hadronic component can be important for ɛe << Vp. This model however demands a very large energy budget. With a large enough Lorentz factor, the PeV photons due to π0 decay may emerge from the internal shocks. Although they would be absorbed by the cosmic microwave background radiations, the secondary emission would contribute to the diffuse γ-ray background.