Interpretation of astrophysical neutrinos observed by IceCube experiment by setting Galactic and extra-Galactic spectral components [HEAP]

The last IceCube catalog of High Energy Starting Events (HESE) obtained with a livetime of 1347 days comprises 54 neutrino events equally-distributed between the three families with energies between 25 TeV and few PeVs. Considering the homogeneous flavors distribution (1:1:1) and the spectral features of these neutrinos the IceCube collaboration claims the astrophysical origin of these events with more than $5\sigma$. The spatial distribution of cited events does not show a clear correlation with known astrophysical accelerators leaving opened both the Galactic and the extra-Galactic origin interpretations. Here, we compute the neutrino diffuse emission of our Galaxy on the basis of a recently proposed phenomenological model characterized by radially-dependent cosmic-ray (CR) transport properties. We show that the astrophysical spectrum measured by IceCube experiment can be well explained adding to the diffuse Galactic neutrino flux (obtained with this new model) a extra-Galactic component derived from the astrophysical muonic neutrinos reconstructed in the Northern hemisphere. A good agreement between the expected astrophysical neutrino flux and the IceCube data is found for the full sky as well as for the Galactic plane region.

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D. Gaggero, D. Grasso, A. Marinelli, et. al.
Thu, 21 Apr 16

Comments: 4 pages, 2 figures, accepted for the VLVnT-2015 Conference proceedings