The Angular Structures of Some Compact Sources

Abstract

From 1965 to 1967 radio link interferometers were operated between Jodrell Bank and Malvern, at wavelengths of 21, 11, and 6 cm. Preliminary results were published by Adgie et al. (1965), Barber et al. (1966), Palmer et al. (1967) and Miley et al. (1967). The full analysis of these data has now been completed. Donaldson et al. (1969) report that six sources were unresolved, and they set size limits in the range 0.1 to 0.01 arc sec. Seven sources were found to contain unresolved components, and similar but less complete data were obtained on 33 other sources. Four sources (3C 119, 138, 147, and 237) were shown to have double or more complex structures. (Donaldson and Smith, 1970; Donaldson et al., 1970). The cores of 3C 274 and four other sources were shown to have elongations in the range 0.3 to 0.03 arc sec. One of these is 3C 287, and when the data on this source are combined with those of Clark et al. (1968) at 1660 MHz it appears that this source is a double of separation 0.08 arc sec in position angle 025°. This differs from the interpretation given by Clark et al. Some new data were also obtained on the well known double sources 3C 405 and 1938-15.