Thermal and non-thermal radio variations in WR 147

Abstract

We present new, high-resolution (70-mas) radio images of the colliding wind system WR 147 observed with Multi-element Radio-linked Interferometer Network (MERLIN), which show significant differences in the structures of both the thermally emitting WN8 stellar component (WR 147S) and the non-thermal wind-collision source (WR 147N). The size and shape of WR 147N change between the first and last epochs, as does the position of the emitting material. The presence of low-intensity emission between WR 147S and WR 147N is confirmed in one 5-GHz epoch, and this, together with the southerly movement of faint emission blobs seen by ourselves and Contreras & Rodríguez, suggests a north–south preferential outflow axis.