Origin of the High Energy Cosmic Neutrino Background

The diffuse background of very high energy extraterrestrial neutrinos recently discovered with IceCube is compatible with that expected from cosmic ray interactions in the Galactic interstellar medium plus that expected from hadronic interactions near the source and in the intergalactic medium of the cosmic rays which have been accelerated by the jets that produce gamma ray bursts.

Figure 1

The redshift distribution of the 262 Swift LGRBs with known redshift that were detected before November 15, 2013 and their expected distribution [25] assuming the rate of GRBs/SNe traces the star formation rate.

Figure 2

Comparison between the flux of an isotropic neutrino background that was inferred from 3 years measurements with IceCube [1], and that expected from cosmic ray production in the Galactic ISM and in the molecular clouds of external galaxies hosting supernovae that produce GRBs.