THE EXTENDED RADIO-EMISSION IN THE LUMINOUS X-RAY-CLUSTER A3667

The radio sources in the galaxy cluster A3667 have been imaged using t he Australia Telescope Compact Array at both 13 and 20 cm. The most st riking source is a large region (at least 2.6 Mpc in extent) of mostly diffuse emission that is located to the north-west, well outside the central core of the cluster. Taking into account the X-ray and optical data, we suggest that turbulence in the outer region of the cluster, associated with a cluster merger, reaccelerates remnant relativistic p articles, leading to the observed large region of radio emission. New MOST data which indicate similar diffuse emission to the south-east su pport this conclusion.