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Register a new userDiscovery of GeV gamma-ray emission from the LMC B0443-6657 with the Fermi Large Area Telescope
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Qing-Wen Tang
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We report the discovery of gamma-ray detection from the Large Magellanic Cloud (LMC) B0443-6657 using the Large Area Telescope (LAT) on board the textit{Fermi Gamma-ray Space Telescope}. LMC B0443-6657 is a flat spectrum radio source, possibly associated with a supernova remnant in the Large Magellanic Cloud (LMC N4). Employing the LAT data of 8 years, our results show a significant excess ($>9.4sigma$) of gamma-ray in the range of 0.2--100,GeV above the gamma-ray background. A power-law function is found to be adequate to describe the $0.2-100$ GeV $gamma$-ray spectrum, which yields a photon flux of $3.27pm0.53 mathrm{photon ,cm}^2 mathrm{s}^{-1}$ with a photon index of $2.35pm0.11$, corresponding to an isotropic gamma-ray luminosity of $5.3times10^{40} mathrm{erg ,s}^{-1}$. The hadronic model predicts a low X-ray and TeV flux while the leptonic model predicts an observable flux in these two energy bands. The follow-up observations of the LMC B0443-6657 in X-ray or TeV band would distinguish the radiation models of gamma-rays from this region.
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