Extragalactic plus Galactic model for IceCube neutrino events

TL;DR

This paper proposes a two-component model combining extragalactic and galactic neutrino sources with distinct energy spectra to better explain IceCube observations, offering testable predictions for future neutrino and gamma-ray telescopes.

Contribution

It introduces a novel two-component model with different spectral indices for extragalactic and galactic neutrinos, improving upon previous single-component models.

Findings

The extragalactic component follows an $E_ u^{-2}$ spectrum.

The galactic component has an $E_ u^{-2.7}$ spectrum.

A diffuse galactic component accounts for 20-30 ext% of IceCube events.

Abstract

The hypothesis that high energy cosmic neutrinos are power law distributed is critically analyzed. We propose a model with two components that explains better the observations. The extragalactic component of the high energy neutrino flux has a canonical $E_\nu^{-2}$ spectrum while the galactic component has a $E_\nu^{-2.7}$ spectrum; both of them are significant. This model has several implications, that can be tested by IceCube and ANTARES in the next years. Moreover, the existence of a diffuse component close to the Galactic plane and that yields (20-30)\% of IceCube's events, is interesting for the future $\mbox{km}^3$ neutrino telescopes located in the Northern Hemisphere and for gamma ray telescopes aiming at measuring events till few 100 TeV from the Southern sky.