Likely Detection of GeV Gamma-Ray Emission from the Composite Supernova Remnant COMP G327.1+1.1 with Fermi-LAT

We report the likely GeV γ-ray emission from the composite supernova remnant (SNR) COMP G327.1+1.1 by analyzing ∼12.2 yr of the Fermi Large Area Telescope (Fermi-LAT) Pass 8 data. We found the features of its spectrum and luminosity are well consistent with those of the observed COMP SNRs in the Milky Way. Moreover, the position of the source matches those in radio and TeV energy bands; we propose that the γ-ray source is likely to be a GeV counterpart of COMP G327.1+1.1. Considering the case of the association from COMP G327.1+1.1 and the γ-ray source, we interpreted its broadband spectral energy distribution (SED) by using three simple stationary models including one-zone and two-zone leptonic models and a one-zone leptohadronic model. We found that the simple two-zone model dominated by leptons can better explain its SED. More high-energy data are expected to firmly confirm the association between the γ-ray source and COMP G327.1+1.1 in the future.