Search for joint multimessenger signals from potential galactic cosmic-ray accelerators with HAWC and IceCube

TL;DR

This study searches for correlated gamma-ray and neutrino signals from galactic cosmic-ray accelerators using HAWC and IceCube data, finding no significant neutrino emission but constraining hadronic contribution in gamma-ray sources.

Contribution

It introduces a multimessenger analysis combining HAWC and IceCube data to investigate galactic cosmic-ray sources, setting limits on hadronic gamma-ray production.

Findings

No significant neutrino emission detected from the sources.

Constraints on the hadronic contribution to gamma-ray emission.

Limits on neutrino flux from 22 gamma-ray sources.

Abstract

The origin of high-energy galactic cosmic rays is yet to be understood, but some galactic cosmic-ray accelerators can accelerate cosmic rays up to PeV energies. The high-energy cosmic rays are expected to interact with the surrounding material or radiation, resulting in the production of gamma-rays and neutrinos. To optimize for the detection of such associated production of gamma-rays and neutrinos for a given source morphology and spectrum, a multimessenger analysis that combines gamma-rays and neutrinos is required. In this study, we use the Multi-Mission Maximum Likelihood framework with IceCube Maximum Likelihood Analysis software and HAWC Accelerated Likelihood to search for a correlation between 22 known gamma-ray sources from the third HAWC gamma-ray catalog and 14 yr of IceCube track-like data. No significant neutrino emission from the direction of the HAWC sources was found. We report the best-fit gamma-ray model and 90% CL neutrino flux limit from the 22 sources. From the neutrino flux limit, we conclude that, for five of the sources, the gamma-ray emission observed by HAWC cannot be produced purely from hadronic interactions. We report the limit for the fraction of gamma-rays produced by hadronic interactions for these five sources.