An X-ray and radio study of the Hubble Frontier Field cluster Abell S1063

Abstract

We present results from Chandra X-ray observations and 325 MHz Giant Metrewave Radio Telescope (GMRT) observations of the massive and X-ray luminous cluster of galaxies Abell S1063. We report the detection of large-scale 'excess brightness' in the residual Chandra X-ray surface brightness map that extends at least 2.7 Mpc towards the north-east from the centre of the cluster. We also present a high fidelity X-ray flux and temperature map using Chandra archival data of 122 ks that shows the disturbed morphology in the cluster. The residual flux map shows the first observational confirmation of the merging axis proposed in earlier simulations. The average temperature within R500 is 11.7 ± 0.56 keV that makes AS1063 one of the hottest clusters in the nearby Universe. The integrated radio flux density at 325 MHz is found to be 62.0 ± 6.3 mJy. The integrated spectrum of the radio halo follows a power law with a spectral index α = -1.43 ± 0.13. The radio halo is found to be significantly under-luminous that favored for both the hadronic as well as the turbulent re-acceleration mechanism for its origin. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.