Interactions between the jet and disk wind in a nearby radio intermediate quasar III Zw 2

TL;DR

This study investigates the interaction between jets and disk winds in the active galactic nucleus III Zw 2, revealing jet-wind collisions, jet ejections, and variability driven by accretion disk instabilities, providing insights into AGN nuclear dynamics.

Contribution

It presents the first detailed analysis of jet-wind interactions in III Zw 2, linking radio and gamma-ray flares to disk instabilities and jet dynamics.

Findings

Jet knots move at 1.35c, indicating superluminal motion.

Gamma-ray flares correlate with jet ejections and collisions.

Disk instabilities modulate jet activity and cause variability.

Abstract

Disk winds and jets are ubiquitous in active galactic nuclei (AGN), and how these two components interact remains an open question. We study the radio properties of a radio-intermediate quasar III Zw 2. We detect two jet knots J1 and J2 on parsec scales, which move at a mildly apparent superluminal speed of $1.35\,c$. Two $\gamma$-ray flares were detected in III Zw 2 in 2009--2010, corresponding to the primary radio flare in late 2009 and the secondary radio flare in early 2010. The primary 2009 flare was found to be associated with the ejection of J2. The secondary 2010 flare occurred at a distance of $\sim$0.3 parsec from the central engine, probably resulting from the collision of the jet with the accretion disk wind. The variability characteristics of III Zw 2 (periodic radio flares, unstable periodicity, multiple quasi-periodic signals and possible harmonic relations between them) can be explained by the global instabilities of the accretion disk. These instabilities originating from the outer part of the warped disk propagate inwards and can lead to modulation of the accretion rate and consequent jet ejection. At the same time, the wobbling of the outer disk may also lead to oscillations of the boundary between the disk wind and the jet tunnel, resulting in changes in the jet-wind collision site. III Zw 2 is one of the few cases observed with jet-wind interactions, and the study in this paper is of general interest for gaining insight into the dynamic processes in the nuclear regions of AGN.