1305.6606 (D. B. Fox et al.)

Sub-PeV Neutrinos from TeV Unidentified Sources in the Galaxy    [PDF]

D. B. Fox, K. Kashiyama, P. Meszaros

The IceCube collaboration discovery of 28 high-energy neutrinos over the energy range 30 TeV <~ e_nu <~ 1 PeV, a 4.3-sigma excess over expected backgrounds, represents the first high-confidence detection of cosmic neutrinos at these energies. In light of this discovery, we construct a model for generating sub-PeV cosmic neutrinos in our Galaxy's TeV unidentified (TeV UnID) sources. While typically resolved at TeV energies, these sources lack radio or X-ray counterparts, and so have been considered promising sites for hadron acceleration within our Galaxy. We find that the observed flux and power-law spectrum of the IceCube Sub-PeV neutrinos are consistent with the properties of the TeV UnID sources under the hadronic acceleration scenario, with the ~1.5 PeV cutoff in the neutrino spectrum indicating acceleration of hadrons to E_max >~ 10 PeV. We review arguments that hypernova remnants provide a plausible astrophysical explanation for the number and properties of these sources. Exploring the spatial distribution of the Sub-PeV neutrinos and TeV UnID sources, we find that a best-fit of two, and maximum of 6.4 (at 90%-confidence), of the Sub-PeV neutrinos may originate in the Galaxy's TeV UnID sources, with the remaining 60% to 90% of events being drawn from an isotropic background. If our scenario is correct, we expect a track-type IceCube Sub-PeV neutrino to be found in coincidence with one of the TeV UnID sources within the next 0.5 to 3.5 years of observations. Our scenario can be further tested via observations of Sub-PeV neutrinos from ANTARES or other facilities, and has implications for observations of the TeV UnID sources at radio, X-ray, and TeV wavelengths.

View original: http://arxiv.org/abs/1305.6606