Speaker
Description
We present MeerKAT 1.28 GHz radio-continuum results for the Frontier Field cluster Abell S1063 at $z = 0.351$. The observations reveal a giant radio halo extending over $\sim 1.96$ Mpc, with an integrated flux density of $S_{1.28\,\mathrm{GHz}} = 15.43 \pm 2.73~\mathrm{mJy}$. Its large physical extent and comparatively low radio power place it among the relatively underluminous giant radio haloes. Its diffuse radio emission broadly follows the distribution of the cluster’s hot X-ray gas, elongated towards the north-east along the proposed merger axis. Combining the MeerKAT measurement with flux-density measurements available in the literature, we find that the integrated radio spectrum steepens above $\sim 1.5 \ \mathrm{GHz}$. The halo morphology, radio–X-ray alignment and curved spectrum are consistent with an ageing relativistic electron population re-accelerated by merger-driven turbulence. We will give consideration of the results together with the 10 subtracted radio galaxies lensed by the cluster.