Correlation between neutrinos and jetted AGN

After a brief introduction to the structure of the jetted (or radio-loud) Active Galactic Nuclei (AGN), we talk about the evidence of relativistic components in the jets. Then we talk about their empirical classification and the hint that brings scientists to a generic unified classification, in particular for the jetted ones. We present the two main models to explain their Spectral Energy Distribution (SED), that is the leptonic and the lepto-hadronic model, in which the principal responsible of the high energy part of the SED are respectively electrons or protons. In these models, the acceleration of the particles takes place in the inner part of the AGN jet, acceleration that is caused by the electromagnetic field formed by the Super Massive Black Hole (SMBH), located in the center of the AGN. When protons become relativistic, neutrinos can be formed through the interaction between a proton and a gamma photon (Bethe-Heitler pair production) or the interaction between two protons. So, we discuss neutrino production and briefly how to estimate their flux. Finally, we talk about the detection methods and the detection through neutrino telescopes, in particular the high-energy events registered by IceCube Neutrino Observatory in 2018 from the blazar TXS 0506+056 and in 2022 from the Seyfert 2 galaxy NGC 1068.