AT20G ivo://nasa.heasarc/at20g NASA/GSFC HEASARC Murphy et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The Australia Telescope 20-GHz Survey (AT20G) is a blind radio survey carried out at 20 GHz with the Australia Telescope Compact Array (ATCA) from 2004 to 2008, and covers the whole sky south of declination 0 degrees. The AT20G source catalogue presented here is an order of magnitude larger than any previous catalogue of high-frequency radio sources, and includes 5890 sources above a 20-GHz flux-density limit of 40 mJy. All AT20G sources have total intensity and polarisation measured at 20 GHz, and most sources south of declination -15 degrees also have near-simultaneous flux-density measurements at 5 and 8 GHz. A total of 1559 sources were detected in polarised total intensity at one or more of the three frequencies. The completeness of the AT20G source catalog is 91% above 100 mJy/beam and 79% above 50 mJy/beam in regions south of Declination -15 degrees. North of -15 degrees, some observations of sources between 14 and 20 hours in RA were lost due to bad weather and could not be repeated, so the catalog completeness is lower in this region. Each detected source was visually inspected as part of the authors' quality control processs, and so the reliability of the final catalog is essentially 100%. This table was created by the HEASARC in March 2010 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/402/2403/">CDS Catalog J/MNRAS/402/2403/</a> file at20gcat.dat. This is a service provided by NASA HEASARC . 2010MNRAS.402.2403M https://heasarc.gsfc.nasa.gov/W3Browse/all/at20g.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=at20g& GET text/xml 180 99999 true 192.748875 -88.69966667 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=at20g GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_at20g&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0166666666666667 X-ray public at20g Australia Telescope 20-GHz (AT20G) Survey Catalog name IAU-Style Source Designation (AT20G JHHMMSS+DDMMSS) meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable flux_1p5_cm Peak Brightness at 20 GHz (mJy/beam) mJy/beam phot.flux.density;em.radio.750-1500MHz int nullable flux_1p5_cm_error Uncertainty in Peak Brightness at 20 GHz (mJy/beam) mJy/beam stat.error;phot.flux.density;em.radio.750-1500MHz short nullable flux_3p5_cm Peak Brightness at 8 GHz (mJy/beam) mJy/beam phot.flux.density;em.radio.6-12GHz short nullable flux_3p5_cm_error Uncertainty in Peak Brightness at 8 GHz (mJy/beam) mJy/beam stat.error;phot.flux.density;em.radio.6-12GHz short nullable pol_flux_6_cm_error Uncertainty in Polarized Flux Density at 5 GHz mJy stat.error;phys.polarization.linear;phot.flux.density;em.radio.3-6GHz short nullable pol_flux_3p5_cm_error Uncertainty in Polarized Flux Density at 8 GHz mJy stat.error;phys.polarization.linear;phot.flux.density;em.radio.6-12GHz short nullable pol_flux_3p5_cm_limit Limit Flag for Polarized Flux Density at 8 GHz meta.code;phys.polarization.linear;phot.flux.density;em.radio.6-12GHz char nullable pol_flux_6_cm Polarized Flux Density (or Limit) at 5 GHz mJy phys.polarization.linear;phot.flux.density short nullable pol_flux_1p5_cm_error Uncertainty in Polarized Flux Density at 20 GHz mJy stat.error;phys.polarization.linear;phot.flux.density;em.radio.12-30GHz short nullable pol_percent_6_cm Fractional Polarization at 5 GHz percent phys.polarization.linear;em.radio.3-6GHz double nullable pol_percent_6_cm_limit Limit Flag for Fractional Polarization at 5 GHz meta.code;phys.polarization.linear;em.radio.3-6GHz char nullable pol_percent_1p5_cm_limit Limit Flag for Fractional Polarization at 20 GHz meta.code;phys.polarization.linear;em.radio.12-30GHz char nullable pol_angle_1p5_cm Position Angle at 20 GHz degree pos.posAng;phys.polarization.linear;em.radio.12-30GHz short nullable lii Galactic Longitude degree pos.galactic.lon double nullable pol_flux_1p5_cm Polarized Flux Density (or Limit) at 20 GHz mJy phys.polarization.linear;phot.flux.density short nullable pol_flux_1p5_cm_limit Limit Flag for Polarized Flux Density at 20 GHz meta.code;phys.polarization.linear;phot.flux.density;em.radio.12-30GHz char nullable pol_angle_6_cm Position Angle at 5 GHz degree pos.posAng;phys.polarization.linear;em.radio.3-6GHz short nullable pol_flux_3p5_cm Polarized Flux Density (or Limit) at 8 GHz mJy phys.polarization.linear;phot.flux.density short nullable pol_percent_3p5_cm Fractional Polarization at 8 GHz percent phys.polarization.linear;em.radio.6-12GHz double nullable pol_percent_1p5_cm Fractional Polarization at 20 GHz percent phys.polarization.linear;em.radio.12-30GHz double nullable flux_6_cm Peak Brightness at 5 GHz (mJy/beam) mJy/beam phot.flux.density;em.radio.3-6GHz int nullable quality_flag Flag [gp] Indicates Quality: g=good, p=poor meta.code.qual char nullable pol_flux_6_cm_limit Limit Flag for Polarized Flux Density at 5 GHz meta.code;phys.polarization.linear;phot.flux.density;em.radio.3-6GHz char nullable source_flags Flags Indicate Classifications of Source meta.code char nullable pol_percent_3p5_cm_limit Limit Flag for Fractional Polarization at 8 GHz meta.code;phys.polarization.linear;em.radio.6-12GHz char nullable pol_angle_3p5_cm Position Angle at 8 GHz degree pos.posAng;phys.polarization.linear;em.radio.6-12GHz short nullable observing_epochs Flags [1-8.] Indicate Epochs of Observation at 20, 8, and 5 GHz time.epoch;obs char nullable bii Galactic Latitude degree pos.galactic.lat double nullable flux_6_cm_error Uncertainty in Peak Brightness at 5 GHz (mJy/beam) mJy/beam stat.error;phot.flux.density;em.radio.3-6GHz short nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable