ATCA observations of the MACS-Planck Radio Halo Cluster Project

II. Radio observations of an intermediate redshift cluster sample^★

¹ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice cedex 4, France
e-mail: gerardo.martinez.aviles@gmail.com
² School of Chemical & Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
³ Peripety Scientific Ltd., PO Box 11355 Manners Street, Wellington 6142, New Zealand
⁴ INAF- Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
⁵ Laboratoire AIM, IRFU/Département d’Astrophysique – CEA/DRF – CNRS – Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
⁶ Department of Physics and Astronomy, UniBO, Via Gobetti 93/2, 40129 Bologna, Italy
⁷ Naval Research Laboratory, 4555 Overlook Avenue SW, Code 7213, Washington, DC 20375, USA
⁸ Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, 91405 Orsay cedex, France
⁹ Department of Physics & Astronomy, University of Iowa, Iowa City, IA 52245, USA
¹⁰ Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333CA Leiden, The Netherlands
¹¹ CNRS, IRAP, 9 avenue Colonel Roche, BP 44346, 31028 Toulouse cedex 4, France
¹² Université de Toulouse, UPS-OMP, IRAP, Toulouse, France

Received: 6 July 2017
Accepted: 6 September 2017

Abstract

Aim. A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the largely unexplored intermediate redshift range (0.3 < z < 0.44).

Methods. In search of diffuse emission, deep radio imaging of the clusters are presented from wide band (1.1–3.1 GHz), full resolution (~5 arcsec) observations with the Australia Telescope Compact Array (ATCA). The visibilities were also imaged at lower resolution after point source modelling and subtraction and after a taper was applied to achieve better sensitivity to low surface brightness diffuse radio emission. In case of non-detection of diffuse sources, we set upper limits for the radio power of injected diffuse radio sources in the field of our observations. Furthermore, we discuss the dynamical state of the observed clusters based on an X-ray morphological analysis with XMM-Newton.

Results. We detect a giant radio halo in PSZ2 G284.97-23.69 (z = 0.39) and a possible diffuse source in the nearly relaxed cluster PSZ2 G262.73-40.92 (z = 0.421). Our sample contains three highly disturbed massive clusters without clear traces of diffuse emission at the observed frequencies. We were able to inject modelled radio haloes with low values of total flux density to set upper detection limits; however, with our high-frequency observations we cannot exclude the presence of RH in these systems because of the sensitivity of our observations in combination with the high z of the observed clusters.