NGC 6251 is a luminous radio galaxy \approx 104 Mpc away that was detected significantly with the Fermi Gamma-ray Space Telescope , and before that with EGRET ( onboard the Compton Gamma-ray Observatory ) .
Different observational constraints favor a nuclear origin for the \gamma -ray emission .
Here we present a study of the spectral energy distribution ( SED ) of the core of NGC 6251 , and give results of modeling in the one-zone synchrotron/SSC framework .
The SSC model provides a good description of the radio to \gamma -ray emission but , as for other misaligned sources , predicts a lower Lorentz factor ( \Gamma \sim 2.4 ) than typically found when modeling blazars .
If the blazar unification scenario is correct , this seems to point to the presence of at least two emitting regions in these objects , one with a higher and one with a lower Lorentz factor .
The solution of a structured jet , with a fast moving spine surrounded by a slow layer , is explored and the consequences of the two models for the jet energetics and evolution are discussed .