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arXiv · 1504.06116

KAT-7 detection of radio halo emission in the Triangulum Australis galaxy cluster

Anna M. M. Scaife·Nadeem Oozeer·Francesco de Gasperin·Marcus Brueggen·Cyril Tasse·Lindsay Magnus
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Abstract

We report the presence of high significance diffuse radio emission from the Triangulum Australis cluster using observations made with the KAT-7 telescope and propose that this emission is a giant radio halo. We compare the radio power from this proposed halo with X-ray and SZ measurements and demonstrate that it is consistent with the established scaling relations for cluster haloes. By combining the X-ray and SZ data we calculate the ratio of non-thermal to thermal electron pressure within Triangulum Australis to be $X=0.658\pm0.054$. We use this ratio to constrain the maximum magnetic field strength within the halo region to be $B_{\rm max, halo} = 33.08\,μ$G and compare this with the minimum field strength from equipartition of $B_{\rm min, halo} = 0.77(1+k)^{2/7}\,μ$G to place limits on the range of allowed magnetic field strength within this cluster. We compare these values to those for more well-studied systems and discuss these results in the context of equipartition of non-thermal energy densities within clusters of galaxies.

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Anna M. M. Scaife, Nadeem Oozeer, Francesco de Gasperin, Marcus Brueggen, Cyril Tasse, Lindsay Magnus. 2015-04-23. KAT-7 detection of radio halo emission in the Triangulum Australis galaxy cluster. https://arxiv.org/abs/1504.06116

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