Lunar occultation observations of twelve 3C sources at 327 MHz

The Ooty radio telescope has been used to observe lunar occultations at 327 MHz of 12 radio sources from the 3C catalogue. Accurate radio positions and structures with resolutions ranging from 0.6 to 4 arcsec are presented for these sources. All the 12 sources, including the strong scintillators 3C 49 and 3C 446, are resolved and exhibit double or more complex structure. For a number of sources the present results are combined with those of IPS and interferometric observations by others in order to derive models for their fine structure. The central component in 3C 207 is found to have a core–halo structure, the halo being $$\sim\,{10}^{3}$$ times larger in size than the core. The compact scintillating components detected by IPS in six wellresolved double sources of the present sample are likely to be bright heads lying at the outer edges, similar to those found in 3C 33 and Cyg A. A new identification has been suggested for 3C 170 which possibly is a head–tail source lying in a cluster of galaxies.