From the ‘blazar sequence' to unification of blazars and radio galaxies

Based on a large Fermi blazar sample, the blazar sequence (synchrotron peak frequency νpeak versus synchrotron peak luminosity Lpeak) is revisited. It is found that there is significant anticorrelation between νpeak and Lpeak for blazars. However, after Doppler correction the anticorrelation disappears. The jet cavity power (Pjet) is estimated from the extended radio luminosity so that it is free of beaming effects. We find that there are significant anticorrelations between Pjet and the beam-corrected |$\nu _{\rm peak}^{^{\prime }}$| for both blazars and radio galaxies, which supports the blazar sequence and the unification of blazars and radio galaxies (an alternative relationship is the correlation between jet power and γ-ray photon index).