A leptonic model for the γ-rays coincident with the tail region of the supernova remnant G106.3+2.7

•100 TeV gamma-rayscoincident with the tail region been detected•A model is proposed to investigate the origin of the gamma-rays The supernova remnant (SNR) G106.3 + 2.7 has a comet-shaped morphology in radio with a head and an elongated tail, and a pulsar PSR J2229 + 6114 is located in the northern boundary of the head. Recently, γ-rays with energies range from GeV to 500 TeV spatially coincident with the tail region have been detected. We investigate whether the γ-rays can be produced by the high-energy electrons/positrons in a nebula powered by PSR J2229 + 6114. Using a one-zone model for the multiband emission from the nebula, the detected radio, X-ray and γ-ray fluxes can be well reproduced with the assumption that a fraction (∼0.12) of the spin-down luminosity is used to power the leptons in the emission zone. The particle spectrum has a break at the lorentz factor γ>108 mainly due to the radiative loss of synchrotron radiation, and the magnetic field strength in the emission zone can be constrained to be ∼4μ G. The result shows that the detected γ-ray spectrum can be well produced via IC scattering of the high-energy electrons/positrons in the nebula which is in the tail region of the remnant.