Kiloparsec scale structure in the hotspots of 3C 196.

The five telescopes of the MERLIN array have been used to observe the radio source 3C 196 at 5 GHz, with an angular resolution of 85 milliarcsec that reveals the presence of complex structure in each of the two bright hot spots (on a scale of less than 1 to 10 kpc). By combining these data with those from previously published maps of the source, spectral index distributions and the position of the radio core component detected by Laing (1982) are obtained, relative to the MERLIN map. While a physical rotation of the source axis with respect to the surrounding medium is the most likely explanation for the rotational symmetry of the radio structure, it is possible that the outflow of material from the hot spots toward the more diffuse emission regions occurs simultaneously with this rotation.