Hydrodynamical backflow in X-shaped radio galaxy PKS 2014−55
Loading...
Date
Authors
Cotton, W.D.
Thorat, Kshitij
Condon, J.J.
Frank, B.S.
Jozsa, Gyula I.G.
White, Sarah V.
Deane, Roger
Oozeer, N.
Atemkeng, M.
Bester, L.
Journal Title
Journal ISSN
Volume Title
Publisher
Oxford University Press
Abstract
We present MeerKAT 1.28 GHz total-intensity, polarization, and spectral-index images
covering the giant (projected length l ≈ 1.57 Mpc) X-shaped radio source PKS 2014−55 with
an unprecedented combination of brightness sensitivity and angular resolution. They show
the clear ‘double boomerang’ morphology of hydrodynamical backflows from the straight
main jets deflected by the large and oblique hot-gas halo of the host galaxy PGC 064440.
The magnetic field orientation in PKS 2014−55 follows the flow lines from the jets through
the secondary wings. The radio source is embedded in faint (Tb ≈ 0.5 K) cocoons having the
uniform brightness temperature and sharp outer edges characteristic of subsonic expansion into
the ambient intragroup medium. The position angle of the much smaller (l ∼ 25 kpc) restarted
central source is within 5◦ of the main jets, ruling out models that invoke jet re-orientation
or two independent jets. Compression and turbulence in the backflows probably produce the
irregular and low polarization bright region behind the apex of each boomerang as well as
several features in the flow with bright heads and dark tails.
Description
Keywords
Hydrodynamics – ISM, Individual objects, PGC 064440 – galaxies, Active – galaxies, Jets – radio continuum, Galaxies – radio lines, Galaxies, MeerKAT radio telescope
Sustainable Development Goals
Citation
Cotton, W.D., Thorat, K., Condon, F.F. et al. 2020, 'Hydrodynamical backflow in X-shaped radio galaxy PKS 2014−55', Monthly Notices of the Royal Astronomical Society, vol. 495, no. 1, pp. 1271-1283.