Faraday rotation study of NGC 612 (PKS 0131-36): a hybrid radio source and its magnetised circumgalactic environment

Abstract

We present a polarization and Faraday rotation study of the hybrid morphology radio galaxy NGC 612 (PKS 0131-36), using Australian Telescope Compact Array observations from 1 to 3 GHz. In general, the results are consistent with an external Faraday screen close to the radio source. In the eastern FRII lobe, the RM of the hotspot increases in magnitude towards the leading edge, as well as changing sign (compared to the rest of the lobe). The Faraday depolarization is also ~3 times larger at the hotspot than elsewhere. A plausible explanation for this is significant compression of ambient magnetised gas by the bow shock produced by the advancing hotspot. The western FRI lobe also exhibits some evidence of interaction with local magnetised gas, as a transverse band of high RM coincides with a distinct bend in the lobe. Previous observations of NGC 612 revealed an HI bridge of tidal debris along the direction of the eastern lobe towards the gas-rich companion NGC 619. We find no clear evidence that ionised gas associated with this bridge is either mixing with or lies in the foreground of the radio source. This is consistent with the absence of HI absorption against the hotspot, and indicates that the tidal debris must lie mostly behind the eastern lobe.

arXiv comment9 pages, 7 figures. Accepted for publication in MNRAS

References in corpus (29)

• Astropy: A Community Python Package for Astronomy
• The many lives of active galactic nuclei: cooling flows, black holes and the luminosities and colours of galaxies
• A Cosmology Calculator for the World Wide Web
• Faraday Rotation Measure Synthesis
• Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters
• The Australia Telescope Compact Array Broadband Backend (CABB)
• Post-correlation radio frequency interference classification methods
• Draping of Cluster Magnetic Fields over Bullets and Bubbles -- Morphology and Dynamic Effects
• Resolving the Radio Source Background: Deeper Understanding Through Confusion
• Relativistic jet feedback in high-redshift galaxies I: Dynamics
• Radio Jets Clearing the Way Through a Galaxy: Watching Feedback in Action
• Complex Faraday depth structure of Active Galactic Nuclei as revealed by broadband radio polarimetry
• Systematic properties of decelerating relativistic jets in low-luminosity radio galaxies
• Structures of the magnetoionic media around the FR I radio galaxies 3C 31 and Hydra A
• Integrated Polarization of Sources at lambda ~1m and New Rotation Measure Ambiguities
• A retrospective view of Miriad
• Shock heating in the nearby radio galaxy NGC 3801
• The properties of the young stellar populations in powerful radio galaxies at low and intermediate redshifts
• Broadband, radio spectro-polarimetric study of 100 radiative-mode and jet-mode AGN
• Ordered magnetic fields around radio galaxies: evidence for interaction with the environment
• A large-scale shock surrounding a powerful radio galaxy
• The magnetized medium around the radio galaxy B2 0755+37: an interaction with the intra-group gas
• Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131-36)
• The interaction between radio lobes and hot gas in the nearby radio galaxies 3C285 and 3C442A
• Polarization asymmetry in CSS sources: evidence of AGN fuel?
• Suzaku View of the Swift/BAT Active Galactic Nuclei. III. Application of Numerical Torus Models to Two Nearly Compton Thick AGNs (NGC 612 and NGC 3081)
• Broadband radio polarimetry of Fornax A, I: Depolarized patches generated by advected thermal material from NGC 1316
• Large-scale HI in nearby radio galaxies (II): the nature of classical low-power radio sources
• Revealing the Faraday Depth Structure of Radio Galaxy NGC 612 with Broad-Band Radio Polarimetric Observations

Cited by in corpus (9)

• New constraints on the magnetization of the cosmic web using LOFAR Faraday rotation observations
• On the impact of magnetic-field models in galaxy clusters on constraints on axion-like particles from the lack of irregularities in high-energy spectra of astrophysical sources
• Evidence for strong intracluster magnetic fields in the early Universe
• Message in a Bottle: Unveiling the Magneto-Ionic Complexity of AGNs through the Stokes QU-Fitting Technique
• A depolarizing HI tidal tail in the western lobe of Fornax A
• Properties of Compact Faint Radio Sources as a Function of Angular Size from Stacking
• Direct High-Resolution Imaging of Earth-Like Exoplanets
• Observations and Simulations of Radio Emission and Magnetic Fields in Minkowski's Object
• Broad-band Radio Polarimetry of disk galaxies and AGN with KAT 7