Speaker
Description
Models of the origin of astrophysical neutrinos with energies from TeVs to PeVs are strongly
constrained by multimessenger observations and population studies. Recent results point to statis-
tically significant associations between these neutrinos and active galactic nuclei (AGN) selected
by their radio flux observed with very-long-baseline interferometry (VLBI). This suggests that the
neutrinos are produced in central parsecs of blazars, AGN with relativistic jets pointing to the
observer. However, conventional AGN models tend to explain only the highest-energy part of the
neutrino flux observationally associated with blazars. Here we discuss in detail how the neutrinos
can be produced in the part of an AGN giving the dominant contribution to the VLBI radio flux,
the radio core located close to the jet base. Physical conditions there differ both from the immediate
environment of the central black hole and from the plasma blobs moving along the jet. Required
neutrino fluxes, considerably smaller than those of photons, can be produced in interactions of
relativistic protons, accelerated closer to the black hole, with radiation in the core
