Speaker
Fabrizio Tavecchio
(Brera Observatory)
Description
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 BL Lac objects, active galactic nuclei
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, as a slow sheath surrounding the jet
or the (likely radiatively ineffcient) accretion
ow.
Primary author
Fabrizio Tavecchio
(Brera Observatory)
