Detection of two TeV shell-type remnants at GeV energies with Fermi-LAT: HESS J1731-347 and SN 1006
Résumé
We report the first high-significance GeV γ-ray detections of supernova remnants HESS J1731−347 and SN 1006, both of which have been previously detected by imaging atmospheric Cherenkov Telescopes above 1 TeV. Using 8 years of Fermi-LAT Pass 8 data at energies between 1 GeV and 2 TeV, we detect emission at the position of HESS J1731−347 with a significance of and a spectral index of . The hardness of the index and the good connection with the TeV spectrum of HESS J1731−347 support an association between the two sources. We also confirm the detection of SN 1006 at with a spectral index of . The northeast (NE) and southwest (SW) limbs of SN 1006 were also fit separately, resulting in the detection of the NE region () and the non-detection of the SW region. The significance of different spectral components for the two limbs is , providing first indications of an asymmetry in the GeV γ-ray emission.