High‐Energy Cosmic Rays from Gamma‐Ray Burst Sources: A Stronger Case

The suggested association between the sources of γ-ray bursts (GRBs) and the sources of ultrahigh-energy cosmic rays (UHECRs) is based on two arguments: (1) the constraints that UHECR sources must satisfy in order to allow proton acceleration to greater than 10 20 eV are similar to those inferred for GRB sources from γ-ray observations, and (2) the average energy generation rate of UHECRs is similar to the γ-ray generation rate of GRBs. We show that recent GRB and UHECR observations strengthen both arguments and hence strengthen the suggested association.