Signatures from a merging galaxy cluster and its AGN population: LOFAR observations of Abell 1682
Journal article, 2019
We present LOFAR data from 110-180 MHz of the merging galaxy cluster Abell 1682, alongside archival optical, radio, and X-ray data. Our images of 6 arcsec in resolution at low frequencies reveal new structures associated with numerous radio galaxies in the cluster. At a resolution of 20 arcsec we see diffuse emission throughout the cluster over hundreds of kiloparsecs, indicating particle acceleration mechanisms are in play as a result of the cluster merger event and powerful active galactic nuclei. We show that a significant part of the cluster emission is from an old radio galaxy with very steep spectrum emission (having a spectral index of α < -2.5). Furthermore, we identify a new region of diffuse steep-spectrum emission (α < -1.1) as a candidate for a radio halo which is co-spatial with the centre of the cluster merger. We suggest its origin as a population of old and mildly relativistic electrons left over from radio galaxies throughout the cluster which have been re-accelerated to higher energies by shocks and turbulence induced by the cluster merger event. We also note the discovery of six new giant radio galaxies in the vicinity of Abell 1682.
Galaxies: clusters: intracluster medium
Galaxies: jets
Galaxies: halos
Radio continuum: galaxies
Radiation mechanisms: non-thermal
Quasars: supermassive black holes
Author
A. O. Clarke
University of Manchester
A. M. M. Scaife
University of Manchester
T. W. Shimwell
Netherlands Institute for Radio Astronomy (ASTRON)
Leiden University
R. van Weeren
Leiden University
A. Bonafede
Istituto nazionale di astrofisica (INAF)
University of Bologna
G. Heald
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Netherlands Institute for Radio Astronomy (ASTRON)
University of Groningen
G. Brunetti
University of Bologna
Istituto nazionale di astrofisica (INAF)
T. Cantwell
University of Manchester
F. De Gasperin
University of Hamburg
M. Brueggen
University of Hamburg
A. Botteon
Istituto nazionale di astrofisica (INAF)
University of Bologna
M. Hoeft
Thüringer Landessternwarte Tautenburg
Cathy Horellou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
R. Cassano
Istituto nazionale di astrofisica (INAF)
University of Bologna
J. J. Harwood
University of Hertfordshire
H. Rottgering
Leiden University
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 627 A176Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Fusion, Plasma and Space Physics
DOI
10.1051/0004-6361/201935584