Hidden Cosmic-Ray Accelerators as an Origin of TeV-PeV Cosmic Neutrinos

A cura di D. Guetta

lunedì 5 ott 2015, 14:00 → 15:30 Europe/Rome

Aula Conversi (Dipartimento di Fisica - Ed. G. Marconi)

The latest IceCube data suggest that the all-flavor cosmic neutrino flux may be as large as 10^{?7} GeV/ cm^2/s/sr around 30 TeV. We show that, if astrophysical sources of the TeV-PeV neutrinos are transparent to gamma rays with respect to two-photon annihilation, a large fraction of the isotropic diffuse -ray background should originate from hadronic emission of such sources, independently of the production mechanism. Strong tensions with the diffuse gamma-ray data are unavoidable especially in hadronuclear (pp) scenarios. We further show that, if the IceCube neutrinos have a photohadronic (p) origin, the sources are expected to be opaque to 1?100 GeV gamma rays. With these general multimessenger arguments, we find that the latest data may indicate a population of CR accelerators hidden in GeV-TeV gamma rays. Searches for x-ray and MeV -ray counterparts are encouraged, and TeV-PeV neutrinos themselves will serve as special probes of dense source environments.