We report on the results from our \gamma -ray analysis of the supernova remnant ( SNR ) RCW 103 region .
The data were taken with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope .
An extended source is found at a position consistent with that of RCW 103 , and its emission was only detected above 1 GeV ( 10 \sigma significance ) , having a power-law spectrum with a photon index of 2.0 \pm 0.1 .
We obtain its 1–300 GeV spectrum , and the total flux gives a luminosity of 8.3 \times 10 ^ { 33 } erg s ^ { -1 } at a source distance of 3.3 kpc .
Given the positional coincidence and property similarities of this source with other SNRs , we identify it as the likely Fermi \gamma -ray counterpart to RCW 103 .
Including radio measurements of RCW 103 , the spectral energy distribution ( SED ) is modeled by considering emission mechanisms based on both hadronic and leptonic scenarios .
We find that models in the two scenarios can reproduce the observed SED , while in the hadronic scenario the existence of SNR–molecular-cloud interaction is suggested as a high density of the target protons is required .