From the "blazar sequence" to unification of blazars and radio galaxies

TL;DR

This study revisits the blazar sequence using a large Fermi blazar sample, revealing that jet power correlates with synchrotron peak frequency after Doppler correction, supporting blazar unification with radio galaxies.

Contribution

It demonstrates that the anti-correlation between peak frequency and luminosity is due to beaming effects, and establishes a link between jet power and peak frequency across blazars and radio galaxies.

Findings

Anti-correlation between $ u_{ m peak}$ and $L_{ m peak}$ disappears after Doppler correction.

Significant anti-correlation between jet power and beam-corrected $ u_{ m peak}$.

Supports unification of blazars and radio galaxies through jet power relationships.

Abstract

Based on a large Fermi blazar sample, the blazar sequence (synchrotron peak frequency $\nu_{\rm peak}$ versus synchrotron peak luminosity $L_{\rm peak}$) is revisited. It is found that there is significant anti-correlation between $\nu_{\rm peak}$ and $L_{\rm peak}$ for blazars. However, after being Doppler corrected, the anti-correlation disappears. The jet cavity power ($P_{\rm jet}$) is estimated from extended radio luminosity. So it is free of beaming effect. We find that there are significant anti-correlations between $P_{\rm jet}$ and beam-corrected $\nu_{\rm peak}^{'}$ for both blazars and radio galaxies, which supports the blazar sequence and unification of blazars and radio galaxies (an alternative relationship is the correlation between jet power and $\gamma$-ray photon index).