A Physical Link Between Jet Formation and Hot Plasma in Active Galactic Nuclei

TL;DR

This study investigates the connection between jet formation and hot plasma in active galactic nuclei, revealing a continuous relation between jet power and X-ray luminosity across different accretion states, similar to X-ray binaries.

Contribution

It demonstrates a consistent correlation between jet power and X-ray luminosity in AGN, supporting a universal link between jet formation and hot plasma conditions across accretion regimes.

Findings

Radio emission correlates with X-ray luminosity as L_R  L_X^(0.6-0.75)

Jet formation is linked to hot, optically thin coronal emission

The relation between jet power and X-ray luminosity is continuous across accretion states

Abstract

Recent observations suggest that in black hole X-ray binaries jet/outflow formation is related to the hot plasma in the vicinity of the black hole, either in the form of an advection-dominated accretion flow at low accretion rates or in a disk corona at high accretion rates. We test the viability of this scenario for supermassive black holes using two samples of active galactic nuclei distinguished by the presence (radio-strong) and absence (radio-weak) of well-collimated, relativistic jets. Each is centered on a narrow range of black hole mass but spans a very broad range of Eddington ratios, effectively simulating, in a statistical manner, the behavior of a single black hole evolving across a wide spread in accretion states. Unlike the relationship between the radio and optical luminosity, which shows an abruptly break between high- and low-luminosity sources at an Eddington ratio of ~1, the radio emission-a measure of the jet power-varies continuously with the hard X-ray (2-10 keV) luminosity, roughly as L_R \propto L_X^(0.6-0.75). This relation, which holds for both radio-weak and radio-strong active galaxies, is similar to the one seen in X-ray binaries. Jet/outflow formation appears to be closely linked to the conditions that give rise to the hot, optically thin coronal emission associated with accretion flows, both in the regime of low and high accretion rates.