Speaker
Description
Active galactic nuclei (AGN) are among the most powerful persistent sources of high-energy electromagnetic radiation in the Universe. The combination of large energy reservoirs, dense radiation fields and ionized plasma in AGN coronae, and relativistic plasma flows in AGN jets makes these systems prime candidates for the production of high-energy neutrinos. Indeed, most of the astrophysical neutrino source associations reported by the IceCube Neutrino Observatory involve AGN. In this talk, I will introduce the key structural components of AGN and outline the physical ingredients underlying multi-messenger models of their emission. I will then present modeling results for AGN jets and coronae, focusing on two representative sources: the GeV gamma-ray-bright blazar TXS 0506+056 and the nearby, TeV gamma-ray-dark Seyfert galaxy NGC 1068. These examples illustrate how neutrino production is shaped by the location of energy dissipation, the properties of the target photon fields, and constraints from X-ray and gamma-ray observations. I will discuss implications for the diffuse neutrino flux and conclude with key open questions in multi-messenger studies of AGN.
