Deep photography of radio sources with the Cambridge CCD system

Preliminary results from a program designed to produce deep images of radio source fields drawn from the Parkes 2700 MHz and Molonglo 408 MHz catalogs using the charge-coupled-device (CCD) camera system are presented. The purpose of the program is to search for faint extensions and nebulosity around radio QSOs and BL Lac objects, and for faint objects in empty radio source fields. The detector and process are described, and the rate during observations was about one event per minute. The results are taken from polaroid photographs of the display screen, and data were also recorded on magnetic tape for later analysis. The nebulosity around the QSO 3C273 is confirmed and shown to extend to a minimum 40 arcsec diameter, but the jet does have a definite outer end. Five faint objects within 35 arcsec of the QSO, which could be associated galaxies, were found. A galaxy around AP Lib was shown to be even larger (25 arcsec minimum) than in previous findings. The 3C273 nebulosity must be considerably larger than AP Lib since it is at more than three times the distance of AP Lib.