Comptonization of Cosmic Microwave Background by Cold Ultrarelativistic Electron-Positron Pulsar Wind and Origin of ~130 GeV Lines

Abstract

Previously, [1] proposed an astrophysical explanation of narrow gamma-ray line-like feature(s) at ∼ 100 GeV from Galactic Center region observed by Fermi/LAT [2]. The model of [1] is based on the inverse Compton scattering of external ultra-violet/X-ray radiation by a cold ultra-relativistic e + -e − pulsar wind. We show that the extra broad ∼30 MeV component should arise from Comptonization of cosmic microwave background radiation. We estimate the main parameters of this component and show that it can be detectable with MeV telescopes such as CGRO/COMPTEL. The location of CGRO/COMPTEL unidentified source GRO J1823-12 close to excess of 105-120 GeV emission (Reg. 1 of [2]) can be interpreted as an argument in favour of astrophysical model of the narrow feature(s) at ∼100 GeV.