Cosmological Gamma-Ray Bursts and the Highest Energy Cosmic Rays

Abstract

We discuss a scenario in which the highest energy cosmic rays (CR's) and cosmological $\gamma$-ray bursts (GRB's) have a common origin. This scenario is consistent with the observed CR flux above 1$0^{20}$ eV, provided that each burst produces similar energies in $\gamma$ rays and in CR's above 1$0^{20}$ eV. Protons may be accelerated by Fermi's mechanism to energies $\sim {10}^{20}\mathrm{eV}$ in a dissipative, ultrarelativistic wind, with luminosity and Lorentz factor high enough to produce a GRB. For a homogeneous GRB distribution, this scenario predicts an isotropic, time-independent CR flux.