Photopion Production in Black-Hole Jets and Flat-Spectrum Radio Quasars as PeV Neutrino Sources

Understand

The IceCube collaboration has reported neutrinos with energies between ~30 TeV and a few PeV that are significantly enhanced over the cosmic-ray induced atmospheric background.

• Viable high-energy neutrino sources must contain very high-energy and ultra-high energy cosmic rays while efficiently making PeV neutrinos.
• Gamma-ray Bursts (GRBs) and blazars have been considered as candidate cosmic-ray accelerators.
• GRBs, including low-luminosity GRBs, can be efficient PeV neutrino emitters for low bulk Lorentz factor outflows, although the photopion production efficiency needs to be tuned to simultaneously explain ultra-high-energy cosmic rays.