Wide-field imaging and polarimetry for the biggest and brightest in the 20-GHz southern sky |
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| Authors: | S Burke-Spolaor R D Ekers M Massardi T Murphy B Partridge R Ricci E M Sadler |
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| Institution: | Haverford College Astronomy Department, 370 Lancaster Avenue, Haverford, PA 19041, USA;Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia;Swinburne University of Technology Centre for Astrophysics and Supercomputing, Hawthorn, VIC 3122, Australia;SISSA/ISAS, Via Beirut 2-4, I-34014 Trieste, Italy;Sydney Institute for Astronomy, The University of Sydney, NSW 2006, Australia;School of Information Technologies, The University of Sydney, NSW 2006, Australia;Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada |
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| Abstract: | We present the wide-field imaging and polarimetry at ν= 20 GHz of seven most extended, bright ( S total≥ 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. |
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| Keywords: | polarization galaxies: active galaxies: magnetic fields cosmic microwave background radio continuum: galaxies |
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