- evn2024@mpifr.de
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Contribution
A search and multi-frequency investigation of the parsec-scale structure of curved jets in AGN
Speakers
- Mr. Vladislav MAKEEV
Primary authors
- Mr. Vladislav MAKEEV (Universität Bonn, MPI für Radioastronomie)
Co-authors
- Prof. Yuri KOVALEV (MPI für Radioastronomie, Lebedev Physical Institute of the Russian Academy of Sciences, Moscow Institute of Physics and Technology)
- Dr. Alexander PUSHKAREV (Crimean Astrophysical Observatory, Lebedev Physical Institute of the Russian Academy of Sciences)
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Content
Very long baseline interferometry (VLBI) observations reveal that active galactic nuclei (AGN) jets often exhibit bending at parsec scales. While individual cases have been studied, broader trends across a large sample remain unclear. We analyse 123,000 multi-frequency VLBI images of 17,000 AGNs. From the total number, we extract 7,927 objects with resolved jet structure, identifying 586 (7% of 7,927) with significantly curved jets and 744 (9% of 7,927) sources with bending signatures.
We use the Astrogeo VLBI FITS images collection (https://astrogeo.org/vlbi_images/), which includes multi-frequency VLBI observations. It covers 2 to 86 GHz and enables us to construct ridgelines of the jets. We utilise precession and Kelvin-Helmholz (KH) instability models to fit jets’ geometry. By analysing these models, we estimate precession periods to be of the order of 100 – 300 yr. Our findings suggest that jet precession, driven by either accretion disk precession for high Eddington accretion rates (> 0.1) or supermassive black hole binaries, can potentially be the cause of the bending. The KH instability also consistently describes the observed structures.
This study explores the physical mechanisms behind AGN jet bending, providing insights into the dynamics of their central supermassive black holes and accretion disks, offering constraints on models of jet precession and instability.