Early science with the Karoo Array Telescope: a mini-halo candidate in galaxy cluster Abell 3667

Abstract

Abell 3667 is among the most well-studied galaxy clusters in the Southern hemisphere. It is known to host two giant radio relics and a head–tail radio galaxy as the brightest cluster galaxy. Recent work has suggested the additional presence of a bridge of diffuse synchrotron emission connecting the north-western radio relic with the cluster centre. In this work, we present full-polarization observations of Abell 3667 conducted with the Karoo Array Telescope at 1.33 and 1.82 GHz. Our results show both radio relics as well as the brightest cluster galaxy. We use ancillary higher resolution data to subtract the emission from this galaxy, revealing a localised excess, which we tentatively identify as a radio mini-halo. This mini-halo candidate has an integrated flux density of 67.2 ± 4.9 mJy beam−1 at 1.37 GHz, corresponding to a radio power of P1.4 GHz = 4.28 ± 0.31 × 1023 W Hz−1, consistent with established trends in mini-halo power scaling