High-Energy Neutrinos from Active Galactic Nuclei

Active Galactic Nuclei (AGN) are sources of high-energy gamma-rays and are considered to be promising candidates to be sources of high-energy cosmic rays and neutrinos as well. We present and discuss various models for ion acceleration and their interactions with matter and radiation leading to high-energy neutrino production. We consider neutrino production mechanisms in both jet-loud and jet-quiet AGN, focusing on disks and coronae in the vicinity of the central black hole, jet regions, and magnetized environments surrounding the AGN. The IceCube Collaboration has reported high-energy neutrino events that may come from both the jet-loud AGN TXS 0506+056 and the jet-quiet AGN NGC 1068. We discuss the implications of these observations themselves as well as the the origins of the all-sky neutrino intensity.