摘要：We report the results of our analysis of the publicly available data obtained by the Large Area Telescope (LAT) on board theFermisatellite towards the direction of the young massive star cluster Westerlund 2. We found significant extendedγ-ray emission in the vicinity of Westerlund 2 with a hard power-law energy spectrum extending from 1 to 250 GeV with a photon index of 2.0 ± 0.1. We argue that amongst several alternatives, the luminous stars in Westerlund 2 are likely sites of acceleration of particles responsible for the diffuseγ-ray emission of the surrounding interstellar medium. In particular, the young star cluster Westerlund 2 can provide sufficient non-thermal energy to account for theγ-ray emission. In this scenario, since theγ-ray production region is significantly larger than the area occupied by the star cluster, we conclude that theγ-ray production is caused by hadronic interactions of accelerated protons and nuclei with the ambient gas. In that case, the total energy budget in relativistic particles is estimated of the order of 1050 erg.
