Formation of very hard electron and gamma-ray spectra of flat-spectrum radio quasars in the fast-cooling regime

  title={Formation of very hard electron and gamma-ray spectra of flat-spectrum radio quasars in the fast-cooling regime},
  author={Dahai Yan and Li Zhang and Shuang-Nan Zhang},
  journal={Monthly Notices of the Royal Astronomical Society},
In external Compton scenario, we investigate the formation of the very hard electron spectrum in the fast-cooling regime, using a time-dependent emission model. It is shown that a very hard electron distribution $N'_{\rm e}(\gp)\propto\gp^{-p}$ with the spectral index $p\sim1.3$ is formed below the minimum energy of injection electron when inverse Compton scattering takes place in the Klein-Nishina regime, i.e., inverse Compton scattering of relativistic electrons on broad-line region radiation… 

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