A VLBI Search for the Origin of Wobbling in Blazar Jets

TL;DR

This study uses long-term VLBA polarimetric observations at 43 GHz to investigate the origin of jet wobbling in four blazars, aiming to understand the inner jet dynamics and their relation to supermassive black hole activity.

Contribution

It introduces a dedicated VLBA monitoring program targeting jet wobbling in blazars, providing new observational data to explore its physical origins and implications.

Findings

Identification of large amplitude jet wobbling in selected blazars

Characterization of the jet structure and core motion over time

Assessment of the program's potential for future high-resolution observations

Abstract

An increasing number of blazars have been reported to show jet wobbling (i.e., non-regular rotations of the structural position angle of their innermost jets in the plane of the sky with amplitudes between 20 deg. and 50 deg., and time scales between 2 yr. and 20 yr.). The physical origin for the observed jet wobbling is still poorly understood, but as this phenomenon is triggered in the innermost regions of the jets, it must be tied to fundamental properties of the inner regions of the accretion system. Thus, jet wobbling may be an interesting potential tool for supermassive black hole, accretion and jet launching studies. As part of a joint theoretical/numerical and observational effort to characterize the observational properties and differences between these three possible scenarios we have started a long-term polarimetric phase-reference 43 GHz VLBA monitoring program to observe the jet structure and the absolute motion of the jet core of four of the blazars which have shown some of the clearest evidence of large amplitude jet wobbling: NRAO 150, OJ 287, 3C 273, and 3C 345 . Here we present this project and we argue about its suitability for future VSOP-2 observations.