Star-forming galaxies as the origin of the IceCube PeV neutrinos

Xiao-Chuan Chang, Ruo-Yu Liu, Xiang-Yu Wang

Published 2014-12-29Version 1

Star-forming galaxies, due to their high star-formation rates and hence large number of supernova remnants therein, are huge reservoirs of cosmic rays (CRs). These CRs collide with the gas in the galaxy and produce high-energy neutrinos through $pp$ collisions. In this paper, we calculate the neutrino production efficiency in star-forming galaxies by considering realistic galaxy properties, such as the gas density and galactic wind properties in star-forming galaxies. To calculate the accumulated neutrino flux, we use the infrared luminosity functions of star-forming galaxies obtained by Herschel PEP/HerMES survey recently. The intensity of CRs producing PeV neutrinos in star-forming galaxies is normalized with the observed CR flux at EeV, assuming that supernovae remnants or hypernova remnants in star-forming galaxies can accelerate protons to EeV energies. Our calculations show that the accumulated neutrino emission produced by CRs in star-forming galaxies can account for the flux and spectrum of the sub-PeV/PeV neutrinos under reasonable assumption about the CR confinement time in these galaxies.