Investigating the correlations between IceCube high-energy neutrinos and Fermi-LAT gamma-ray observations

TL;DR

This study analyzes a decade of IceCube neutrino data in conjunction with Fermi-LAT gamma-ray catalogs to investigate potential source correlations, finding no significant associations but setting upper limits on source contributions to the neutrino flux.

Contribution

It provides the first comprehensive correlation analysis using 10 years of data across multiple gamma-ray source samples, improving constraints on source contributions to high-energy neutrinos.

Findings

No significant correlation between gamma-ray sources and neutrinos.

Each source population contributes no more than 2.5%-36% to the diffuse neutrino flux.

Constraints are improved by a factor of 2 compared to previous 3-year analyses.

Abstract

We use 10 years of publicly available IceCube data to investigate the correlations between high-energy neutrinos and various Fermi-LAT gamma-ray samples. This work considers the following gamma-ray samples: the third Fermi-LAT catalog of high-energy sources(3FHL), >100GeV Fermi-LAT events, LAT 12-year source catalog(4FGL), the fourth catalog of active galactic nuclei(4LAC) and subsets of these samples. For each sample, both a single-source analysis and a stacking analysis are performed. We find no indication that the sources in these samples produce significant high-energy neutrinos. From the null search results, we infer that each source population can produce no more than ~2.5%-36%(at the 95% confidence level, for a spectral index of -2.5) of the IceCube's diffuse neutrino flux. Since we are using a larger (10years) dataset of IceCube neutrinos the constraints are improved by a factor of ~2 compared to those based on 3 years of data.