University of Hertfordshire

From the same journal

From the same journal

By the same authors


  • A. O. Clarke
  • Anna M.M. Scaife
  • T. Shimwell
  • R. J. van Weeren
  • A. Bonafede
  • George Heald
  • G. Brunetti
  • T. M. Cantwell
  • F. de Gasperin
  • M. Brüggen
  • A. Botteon
  • M. Hoeft
  • C. Horellou
  • R. Cassano
  • J. J. Harwood
  • H. J. A. Röttgering
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Original languageEnglish
Article numberA176
Number of pages14
JournalAstronomy & Astrophysics
Journal publication date5 Jul 2019
Early online date4 Jul 2019
Publication statusPublished - 5 Jul 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.


Reproduced with permission from Astronomy & Astrophysics. © 2019 ESO

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