Xiu-Rong Mo | Searcharxiv

arXiv2024

Morphology Study for GeV Emission of the Nearby Supernova Remnant G332.5-5.6

Spatial template is important to study the nearby supernova remnant (SNR). For SNR G332.5-5.6, we report a gaussian disk with radius of about 1.06 degrees to be a potential good spatial model in the gamma-ray band. Employing this new gaussian disk, its GeV lightcurve shows a significant variability of about 7 sigma. The $\gamma$-ray observations of this SNR could be explained well either by a leptonic model or a hadronic model, in which a flat spectrum for the ejected electrons/protons.

astro-ph.HE↗

arXiv2022

Possible Origin of a Newly Discovered GeV Gamma-ray Source Fermi J1242.5+3236

Based on the first 13.4 yr of Fermi science data in the energy range from 300 MeV to 500 GeV, we discovered a bright GeV gamma-ray source with a $\sim$5.64 $\sigma$ detection, named Fermi J1242.5+3236, which has an offset of about 0fdg0996 from a nearby star-forming galaxy NGC 4631. When using the 12-yr data, the detection significance of Fermi J1242.5+3236 is about 4.72 $\sigma$. Fermi J1242.5+3236 is a steady point source without significant temporal variability and has a hard gamma-ray photon index of about -1.60 $\pm$0.24. The spatial offset and the hard gamma-ray spectrum disfavor this source as the diffuse gamma-ray emission from this galaxy. This new source might have a possible origin of an unidentified background blazar, which is more likely a high-synchrotron-peaked blazar for its hard gamma-ray photon index. A follow-up optical observation would help distinguish origin of Fermi J1242.5+3236.

astro-ph.HE↗