IceCube Neutrino Events from Fermi Bubbles

TL;DR

This paper investigates the potential of IceCube to detect neutrinos from Fermi Bubbles, suggesting that up to 7 of the observed high-energy events could originate from these structures, especially under certain cosmic-ray spectrum assumptions.

Contribution

It analyzes the detectability of Fermi Bubbles by IceCube and estimates the number of neutrino events that could be attributed to them based on different cosmic-ray spectra.

Findings

Up to 6-7 of the 37 IceCube events may originate from Fermi Bubbles.

Detection likelihood depends on the cosmic-ray spectrum and cutoff energy.

A hard spectrum with high cutoff energy significantly enhances detection prospects.

Abstract

The IceCube Neutrino Observatory announced thirty-seven candidate events observed with deposited energies above $\sim$ 30 TeV with three-year dataset, more than expected from atmospheric backgrounds. We discuss the detectability of the Fermi Bubbles (FB) by IceCube and show that up to 6 -- 7 of the 37 events could originate from the FB. If the observed gamma rays from the FB are created due to baryonic mechanism, high-energy ($>$ GeV) neutrinos should be emitted as a counterpart. These neutrinos should be detectable as shower- or track-like events at a Km$^3$ neutrino detector. For a hard primary cosmic-ray proton spectrum, $E^{-2.1}$, and cutoff energy at or above 10 PeV, the FB flux substantially exceeds the atmospheric backgrounds. For a steeper spectrum, $E^{-2.3}$, and/or lower cutoff energy, detection with high significance will require a longer running time.