Directional association of TeV to PeV astrophysical neutrinos with radio blazars

Abstract: Recently we have shown that high-energy neutrinos above 200 TeV detected by IceCube are produced within several parsecs in the central regions of radio-bright blazars, that is active galactic nuclei with jets pointing towards us. To independently test this result and extend the analysis to a wider energy range, we use public data for all neutrino energies from seven years of IceCube observations. The IceCube point-source likelihood map is analyzed against the positions of blazars from a statistically complete sample selected by their compact radio flux density. The latter analysis delivers a 3.0 sigma significance with the combined post-trial significance of both studies being 4.1 sigma. The correlation is driven by a large number of blazars. Together with fainter but physically similar sources not included in the sample, they may explain the entire IceCube astrophysical neutrino flux as derived from muon-track analyses. The neutrinos can be produced in interactions of relativistic protons with X-ray self-Compton photons in parsec-scale blazar jets.