PIANO, GiovanniGiovanniPIANOCARDILLO , MARTINAMARTINACARDILLOPILIA, MauraMauraPILIATrois, A.A.TroisGIULIANI, ANDREAANDREAGIULIANIBULGARELLI, ANDREAANDREABULGARELLIPARMIGGIANI, NICOLONICOLOPARMIGGIANITAVANI, MARCOMARCOTAVANI2021-01-072021-01-0720190004-637Xhttp://hdl.handle.net/20.500.12386/29521We present a study of the γ-ray emission detected by the Astrorivelatore Gamma ad Immagini LEggero-Gamma Ray Imaging Detector (AGILE-GRID) from the region of the SNR G78.2+2.1 (Gamma Cygni). In order to investigate the possible presence of γ rays associated with the SNR below 1 GeV, it is necessary to analyze the γ-ray radiation underlying the strong emission from the pulsar PSR J2021+4026, which totally dominates the field. An “off-pulse” analysis has been carried out, by considering only the emission related to the pulsar off-pulse phase of the AGILE-GRID light curve. We found that the resulting off-pulsed emission in the region of the SNR—detected by the AGILE-GRID above 400 MeV—partially overlaps the radio shell boundary. By analyzing the averaged emission on the whole angular extent of the SNR, we found that a lepton-dominated double-population scenario can account for the radio and γ-ray emission from the source. In particular, the MeV-GeV averaged emission can be explained mostly by Bremsstrahlung processes in a high density medium, whereas the GeV-TeV radiation can be explained by both Bremsstrahlung (E ≲ 250 GeV) and inverse Compton processes (E ≳ 250 GeV) in a lower density medium.STAMPAenArticle10.3847/1538-4357/ab1f692-s2.0-85069514252000471624300003https://iopscience.iop.org/article/10.3847/1538-4357/ab1f692019ApJ...878...54PFIS/05 - ASTRONOMIA E ASTROFISICA