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arXiv · 1603.07595

A KAT-7 view of a low-mass sample of galaxy clusters

G. Bernardi·T. Venturi·R. Cassano·D. Dallacasa·G. Brunetti·V. Cuciti·M. Johnston-Hollitt·N. Oozeer·O. M. Smirnov
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Abstract

Radio observations over the last two decades have provided evidence that diffuse synchrotron emission in the form of megaparsec-scale radio halos in galaxy clusters is likely tracing regions of the intracluster medium where relativistic particles are accelerated during cluster mergers. In this paper we present results of a survey of 14 galaxy clusters carried out with the 7-element Karoo Array Telescope at 1.86 GHz, aimed to extend the current studies of radio halo occurrence to systems with lower masses (M$_{\rm 500} > 4\times10^{14}$ M${_\odot}$). We found upper limits at the $0.6 - 1.9 \times 10^{24}$ Watt Hz$^{-1}$ level for $\sim 50\%$ of the sample, confirming that bright radio halos in less massive galaxy clusters are statistically rare.

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G. Bernardi, T. Venturi, R. Cassano, D. Dallacasa, G. Brunetti, V. Cuciti, M. Johnston-Hollitt, N. Oozeer, O. M. Smirnov. 2016-03-24. A KAT-7 view of a low-mass sample of galaxy clusters. https://arxiv.org/abs/1603.07595

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