Neutrino production from photo-hadronic interactions of the gamma flux from Active Galactic Nuclei with their gas content

The diffuse neutrino flux from FRI and BL Lac type galaxies generated from interactions of their own γ radiation with the gas and dust at the sources is reported. This ν-production channel has not been studied in detail up to now. The calculations are based on individual estimations of the neutrino flux in two nearby AGN’s: Centaurus A and M87, assuming the validity of the AGN unification model. The predictions for Centaurus A and M87 involved the parameterization of the measured gamma-ray luminosities and the modeling of the material of the galaxies both based on observations performed by several detectors. No hadronic origin for the TeV photons is assumed. The results show that, although the corresponding ν   flux (E2Φν+ν¯≲10-13s-1sr-1GeVcm-2) is not competitive at high-energies (ϵν≳1TeV) with that from hadronic models, FRI and BL Lac galaxies with γ emission should be already contributing to the diffuse flux of neutrinos in the universe.

► Neutrino production from FRI and BL Lac’s is investigated. ► Only interactions of their γ emission with gas and dust at source are considered. ► Centaurus A and M87 are modeled and used as reference. ► FRI and BL Lac’s should be already contributing to the diffuse neutrino flux. ► However, this flux is too small and below modern experimental limits.