High energy neutrinos from active galactic nuclei
2020-02-06
16:00
UB
Seminari DAM (724, ICC building, UB Campus)
Despite intense inquiry, the sources at the origin of the high-energy neutrinos revealed by IceCube are still unknown. The potential correlation of an IceCube event with a flaring gamma-ray source has recently focused the attention on blazars, active galactic nuclei (AGN) with a relativistic jet pointing to the Earth.
Since the nuclei of these sources lack bright thermal components, it is generally expected that, for acceptable values of the high-energy proton luminosity, the neutrino output (mediated by photopion reactions with photons produced within the jet) is low. I will discuss how this problem can be overcome considering alternative sources of soft photons external to the jet.