Constraints on the origins of the Galactic neutrino flux

TL;DR

This paper establishes a lower limit of at least 8 Galactic sources responsible for the neutrino emission detected by IceCube, using simulations and statistical analysis to constrain source contributions.

Contribution

It introduces a simulation framework to estimate the minimum number of Galactic neutrino sources explaining IceCube observations, accounting for biases and flux fluctuations.

Findings

At least 8 sources are needed to explain the Galactic neutrino emission.

Each source has a luminosity of approximately 1.6 x 10^35 erg/s.

The method constrains both discrete sources and diffuse emission points.

Abstract

Galactic and extragalactic objects in the universe are sources of high-energy neutrinos {that may contribute to the astrophysical neutrino signal seen by IceCube.} Recently, a study done using cascade-like events seen by IceCube reported neutrino emission from the Galactic plane with $>$4$\sigma$ significance. In this work, we put a lower limit on the number of Galactic sources required to explain this emission. To achieve this, we {use} a simulation package created to simulate point sources in the Galaxy along with the neutrino and gamma-ray flux emissions originating from them. Along with {using} past IceCube discovery potential curves, we also account for Eddington bias effects due to Poisson fluctuations in the number of detected neutrino events.{We present a toy Monte Carlo simulation to show that there should be at least 8 sources, each with luminosities $1.6 \times 10^{35}$erg/s responsible for the Galactic neutrino emission. } Our results constrain the number of individual point-like emission regions, which applies both to discrete astrophysical sources and to individual points of diffuse emission.