Revisiting the Fundamental Planes of Black Hole Activity for Strong Jet Sources

TL;DR

This study investigates the origin of X-ray emissions in strong jet sources, finding they are primarily jet-dominated with a hybrid jet+disk mode, and establishes their intrinsic radio--X-ray correlation and fundamental plane after correcting for Doppler boosting.

Contribution

It constructs a large sample of strong jet sources and derives their intrinsic radio--X-ray correlation and fundamental plane, accounting for Doppler boosting effects, revealing the jet-dominated nature of X-ray emissions.

Findings

X-ray emissions are mainly jet-dominated.

Intrinsic radio--X-ray correlation: L_R,int ∝ L_X,int^1.04.

Fundamental plane: log L_R,int = 1.07 log L_X,int - 0.22 log M_BH.

Abstract

Whether the X-ray emissions of strong jet sources originate from disk+coronas or jets is still controversial. In this work, we constructed a strong jet sample containing 50 flat-spectrum radio quasars, 51 low-synchrotron-peaked BL Lac objects and 18 intermediate-synchrotron-peaked BL Lac objects to explore the origin of X-ray emissions. Generally, blazars are the typical radio-loud active galactic nucleus with a powerful jet toward the observer, causing their broadband emissions to be boosted. By considering the Doppler boosting effect, we obtain the intrinsic radio--X-ray correlation and the fundamental plane (FP) of black hole activity for the strong jet sources: the intrinsic radio--X-ray correlation is $L_{\rm{R,int}}\propto L_{\rm{X,int}}^{1.04}$, which favor the jet-dominated mode, the intrinsic FP is $\log L_{\rm{R,int}}=(1.07\pm0.06)\log L_{\rm{X,int}}-(0.22\pm0.10)\log M_{\rm{BH}}-(3.77\pm2.11)$, which can be interpreted by the hybrid mode of jet+standard disk. Our results suggest that the X-ray emissions of strong jet sources are dominated by the jets, but there may also be a small contribution from the disk. In addition, the radio--X-ray correlation and FP of strong jet sources do not have a significant dependence on the Eddington-ratio.