Radio multifrequency observations of Abell 781 with the WSRT
Venturi, T.; Dallacasa, D.; Bernardi, G.; Smirnov, O. M.; Murgia, M.; Hugo, B.; Pizzo, R. F.
South Africa, Italy, Netherlands
Abstract
The Main galaxy cluster in the Abell 781 system is undergoing a significant merger and accretion process with peripheral emission to the north and south-eastern flanks of the merging structure. Here we present a full polarimetric study of this field, using radio interferometric data taken at 21 and 92 cm with the Westerbork Synthesis Radio Telescope (WSRT), to a sensitivity better than any 21 cm (L band) observation to date. We detect evidence of extended low-level emission of 1.9 mJy associated with the Main cluster at 21 cm, although this detection necessitates further follow-up by modern instruments due to the limited resolution of the WSRT. Our polarimetric study indicates that, most likely, the peripheral emission associated with this cluster is not a radio relic.