Diffuse radio emission in a REFLEX cluster

Deep Very Large Array radio observations are presented for the REFLEX clusters RXC J0437.1+0043 and RXC J1314.4-2515. They are at similar distances and show similar X-ray luminosity, but they are quite different in X-ray structure. Indeed RXC J0437.1+0043 is regular and relaxed, whereas RXC J1314.4-2515 is characterized by substructure and possible merging processes. The radio images reveal the lack of diffuse emission in RXC J0437.1+0043 and the presence of a complex diffuse structure in RXC J1314.4-2515. The diffuse source in the latter cluster consists of a central radio halo which extends to the West toward the cluster periphery and bends to the North to form a possible relic. Another extended source is detected in the eastern cluster peripheral region. Although there could be plausible optical identifications for this source, it might also be a relic candidate owing to its very steep spectrum. The present results confirm the tight link between diffuse cluster radio sources and cluster merger processes.