Limits on source distances for the most energetic cosmic rays in intergalactic magnetic fields

Abstract

The propagation of the highest energy cosmic rays through the intergalactic magnetic field is considered, including the effect of interactions with the 2.7 K microwave background. Energy loss in the microwave background due to photo-pion production limits the total distance travelled by the cosmic rays and the turbulent intergalactic field determines their total displacement. At energies above 1020 eV, the average displacements are a few tens of megaparsecs, limiting possible sources to the volume dominated by the supergalactic plane. © 1997 Elsevier Science B.V.