"AGN jets as the origin of UHECRs and perspectives for the detection of EeV astrophysical neutrinos"
Xaiver Rodrigues (DESY)
We demonstrate that a population of Active Galactic Nuclei (AGN) can describe the observed spectrum of ultra-high-energy cosmic rays (UHECRs) at and above the ankle, and that the dominant contribution comes from low-luminosity BL Lacs. Such an AGN-only scenario is in tension with UHECR composition observations above 10 EeV. However, a sub-dominant contribution from high-luminosity AGN reduces this tension and leads simultaneously to a substantial neutrino flux that peaks at EeV energies. The same emission also extends down to PeV energies, and is therefore constrained by current IceCube limits. We also show that the flux of neutrinos emitted from within the sources should outshine the cosmogenic neutrinos produced during the propagation of UHECRs. This result has profound implications for ultra-high-energy (∼EeV) neutrino experiments, since additional search strategies can be used for source neutrinos compared to cosmogenic neutrinos, such as stacking searches, flare analyses, and multi-messenger follow-ups.