Dynamical analysis of the complex radio structure in 3C 293: Clues on a rapid jet realignment in X-shaped radio galaxies

Abstract

Radio galaxies classified as X-shaped/winged, are characterised by two pairs of extended and misaligned lobes, which suggest a rapid realignment of the jet axis, for which a potential cause is still under debate. Here we analyse the complex radio structure of 3C 293 winged source hosted by the post-merger galaxy, which uniquely displays a significant asymmetry between the sizes of the two pairs of lobes, indicating that an episode of jet realignment took place only very recently. Based on all the available radio data for 3C 293, we have performed a detailed spectral modelling for the older and younger lobes in the system. In this way we derived the lobes' ages and jet energetics, which we then compared to the accretion power in the source. We found that the 200 kpc-scale outer lobes of 3C 293 are ~60 Myr old and that jet activity related to the formation of the outer lobes ceased within the last Myr. Meanwhile, the inner 4 kpc-scale lobes, tilted by ~40 deg with respect to the outer ones, are only about ~0.3 Myr old. The best model fits also return identical values of the jet power supplying the outer and the inner structures. This power is of the order of the maximum kinetic luminosity of a Blandford-Znajek jet for a given black hole mass and accretion rate, but only in the case of relatively low values of a black hole spin, a~0.2. The derived jet energetics and timescales, along with the presence of two optical nuclei in 3C 293, all provide a strong support to the Lense-Thirring precession model in which the supermassive black hole spin, and therefore the jet axis, flips rapidly owing to the interactions with the tilted accretion disk in a new tidal interaction episode of the merging process. We further speculate that, in general, X-shape radio morphology forms in post-merger systems that are rich in cold molecular gas, and only host slowly spinning supermassive black holes.

Astronomy & Astrophysics, in press

References in corpus (9)

• A close-pair binary in a distant triple supermassive black-hole system
• The intracluster magnetic field power spectrum in Abell 2382
• FIRST `Winged' and `X'-shaped Radio Source Candidates
• GMRT observations of X-shaped radio sources
• X-ray Detection of the Proto Supermassive Binary Black Hole at the Centre of Abell 400
• Recent star formation in nearby 3CR radio-galaxies from UV HST observations
• A method of estimation of the dynamical age of FR II-type radio sources from multifrequency data
• Jet-ISM Interaction in the Radio Galaxy 3C293: Jet-driven Shocks Heat ISM to Power X-ray and Molecular H2 emission
• Starbursts and black hole masses in X-shaped radio galaxies: Signatures of a merger event?

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