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.

Radio continuum: galaxies

Galaxies: halos

Galaxies: clusters: intracluster medium

Radiation mechanisms: non-thermal

Galaxies: jets

Quasars: supermassive black holes


A. O. Clarke

University of Manchester

A. M. M. Scaife

University of Manchester

T. W. Shimwell

Leiden University

Netherlands Institute for Radio Astronomy (ASTRON)

R. van Weeren

Leiden University

A. Bonafede

University of Bologna

INAF OAS Bologna

G. Heald

CSIRO Astronomy and Space Science

Netherlands Institute for Radio Astronomy (ASTRON)

University of Groningen

G. Brunetti

INAF OAS Bologna

University of Bologna

T. Cantwell

University of Manchester

F. De Gasperin

Universität Hamburg

M. Brueggen

Universität Hamburg

A. Botteon

INAF OAS Bologna

University of Bologna

M. Hoeft

Thüringer Landessternwarte Tautenburg

Cathy Horellou

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

R. Cassano

INAF OAS Bologna

University of Bologna

J. J. Harwood

University of Hertfordshire

H. Rottgering

Leiden University

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 627 A176

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Fusion, Plasma and Space Physics



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