Wide-field imaging and polarimetry for the biggest and brightest in the 20-GHz southern sky

Abstract

We present the wide-field imaging and polarimetry at ν = 20 GHz of seven most extended, bright (Stotal ≥ 0.50 Jy), high-frequency selected radio sources in the southern sky with declinations δ < -30°. Accompanying the data are brief reviews of the literature for each source. The results presented here aid in the statistical completeness of the Australia Telescope 20-GHz Survey: the Bright Source Sample. The data are of crucial interest for future cosmic microwave background missions as a collection of information about candidate calibrator sources. We were able to obtain data for seven of the nine sources identified by our selection criteria. We report that Pictor A is thus far the best extragalactic calibrator candidate for the Low Frequency Instrument of the Planck European Space Agency mission due to its high level of integrated polarized flux density (∼0.50 ± 0.06 Jy) on a scale of 10 arcmin. Six out of the seven sources have a clearly detected compact radio core in our images, with either a null detection or less than 2 per cent detection of polarized emission from the nuclei. Most sources with detected jets have magnetic field alignments running in a longitudinal configuration, however, PKS 1333-33 exhibits transverse fields and an orthogonal change in field geometry from nucleus to jets. © 2009 RAS.