A model is presented for the origin of cosmic rays (CRs) from 1e14 eV to the highest energies, >1e20 eV. Gamma-Ray Bursts (GRBs) are assumed to inject CR protons and ions into the interstellar medium of star-forming galaxies--including the Milky Way--with a power law spectrum extending to a maximum energy 1e20 eV. The CR spectrum near the "knee" at 3e15 eV is fit with CRs trapped in the Galactic halo that were injected by an earlier Galactic GRB. Ultra-high energy CRs (UHECRs), with energies above the "ankle" at 3e19 eV are assumed to propagate rectilinearly with their spectrum modified by photo-pion, photo-pair, and expansion losses. The measured UHECR spectrum is fit assuming comoving luminosity densities of GRBs that follow extremes of the possible star formation rate histories of the universe. For injection spectra p>2, we find that the required local GRB luminosity density in non-thermal hadrons must be a factor ~60-200 greater than that measured in gamma-rays. This result implies that 100 TeV-100 PeV could be detected several times per year from individual GRBs in kilometer-scale neutrino telescopes such as IceCube. We argue that the recent detection of a hard MeV component in GRB 941017 reveals a high-energy hadron component in GRB blast waves.

Learn more about the newly-released books The Edge of Infinity: Supermassive Black Holes and The Black Hole at the Center of Our Galaxy