Neutrinos from gamma-ray bursts: propagation of cosmic rays in their host galaxies

Understand

Gamma-ray bursts (GRBs) are proposed as candidate sources of ultra-high energy cosmic rays (UHECRs).

• We study the possibility that the PeV neutrinos recently observed by IceCube are produced by GRB cosmic rays interacting with the interstellar gas in the host galaxies.
• By studying the relation between the X-ray absorption column density N_H and the surface star-formation rate of GRB host galaxies, we find that N_H is a good indicator of the surface gas density of the host galaxies.
• Then we are able to calculate the neutrino production efficiency of CRs for GRBs with known N_H.