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arXiv · 1608.06857

ATCA observations of the MACS-Planck Radio Halo Cluster Project - I. New detection of a radio halo in PLCK G285.0-23.7

Gerardo Martinez Aviles·Chiara Ferrari·Melanie Johnston-Hollitt·Luke Pratley·Giulia Macario·Tiziana Venturi·Gianfranco Brunetti·Rossella Cassano·Daniele Dallacasa·Huib Intema·Simona Giacintucci·Guillaume Hurier·Nabila Aghanim·Marian Douspis·Mathieu Langer
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Abstract

We investigate the possible presence of diffuse radio emission in the intermediate redshift, massive cluster PLCK G285.0-23.7 (z=0.39, M_500 = 8.39 x 10^(14) M_Sun). Our 16cm-band ATCA observations of PLCK G285.0-23.7 allow us to reach a rms noise level of ~11 microJy/beam on the wide-band (1.1-3.1 GHz), full-resolution (~5 arcsec) image of the cluster, making it one of the deepest ATCA images yet published. We also re-image visibilities at lower resolution in order to achieve a better sensitivity to low-surface-brightness extended radio sources. We detect one of the lowest luminosity radio halos known at z>0.35, characterised by a slight offset from the well-studied 1.4 GHz radio power vs. cluster mass correlation. Similarly to most known radio-loud clusters (i.e. those hosting diffuse non-thermal sources), PLCK G285.0-23.7 has a disturbed dynamical state. Our analysis reveals a similarly elongated X-ray and radio morphology. While the size of the radio halo in PLCK G285.0-23.7 is smaller than lower redshift radio-loud clusters in the same mass range, it shows a similar correlation with the cluster virial radius, as expected in the framework of hierarchical structure formation.

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Gerardo Martinez Aviles, Chiara Ferrari, Melanie Johnston-Hollitt, Luke Pratley, Giulia Macario, Tiziana Venturi, Gianfranco Brunetti, Rossella Cassano, Daniele Dallacasa, Huib Intema, Simona Giacintucci, Guillaume Hurier, Nabila Aghanim, Marian Douspis, Mathieu Langer. 2016-08-24. ATCA observations of the MACS-Planck Radio Halo Cluster Project - I. New detection of a radio halo in PLCK G285.0-23.7. https://doi.org/10.1051/0004-6361%2F201628788

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