Constraints on Hadronic Contribution to LHAASO Sources with Neutrino Observations

Abstract

LHAASO detected 12 gamma-ray sources above 100 TeV which are the possible origins of Galactic cosmic-rays. We summarize the neutrino measurements by IceCube and ANTARES in the vicinity of LHAASO sources to constrain the contribution of hadronic gamma-rays in these sources. We find that the current observations constrain that the hadronic gamma-rays contribute no more than ~60% of the gamma-rays from Crab Nebula. Gamma-rays from two LHAASO sources, LHAASO J1825-1326 and LHAASO J1907+0626, are dominated by leptonic components up to ~200 TeV, under the hypotheses in the analysis by IceCube. The uncertainties of the constraint on the hadronic gamma-ray emission are discussed. We also constrain the total 100 TeV gamma-ray emission from TeV PWNe relying on the remarkable sensitivity of LHAASO at that energies.