ATCDFSSS82 ivo://nasa.heasarc/atcdfsss82 NASA/GSFC HEASARC Franzen et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains a source catalog, one of the first results from a deep, blind radio survey carried out at 20 GHz with the Australia Telescope Compact Array, with follow-up observations at 5.5, 9 and 18 GHz. The Australia Telescope 20GHz (AT20G) deep pilot survey covers a total area of 5 deg<sup>2</sup> in the Chandra Deep Field South and in Stripe 82 of the Sloan Digital Sky Survey. The authors estimate the survey to be 90% complete above 2.5 mJy. Of the 85 sources detected, 55% have steep spectra (spectral index alpha<sub>1.4</sub><sup>20</sup> < -0.5) and 45% have flat or inverted spectra (alpha<sub>1.4</sub><sup>20</sup> >= -0.5). The steep-spectrum sources tend to have single power-law spectra between 1.4 and 18 GHz, while the spectral indices of the flat- or inverted-spectrum sources tend to steepen with frequency. Among the 18 inverted-spectrum (alpha<sub>1.4</sub><sup>20</sup> >= 0.0) sources, 10 have clearly defined peaks in their spectra with alpha<sub>1.4</sub><sup>5.5</sup> > 0.15 and alpha<sub>9</sub><sup>18</sup> < -0.15. On a 3-yr time-scale, at least 10 sources varied by more than 15 percent at 20 GHz, showing that variability is still common at the low flux densities probed by the AT20G-Deep Pilot (AT20GDP) survey. The AT20G-Deep Pilot survey was carried out with he ATCA in 2009 July, shortly after the telescope was provided with a new wide-bandwidth correlator, the CABB. As a result of this upgrade to the telescope, the observing bandwidth was increased by a factor of 16, from 2x128 to 2x2048 MHz, in all bands (ranging from 1.1 to 105 GHz), greatly increasing the sensitivity of continuum observations. These observations were made in continuum mode using two 2048-MHz CABB bands centered at 19 and 21 GHz, with each 2048-MHz band divided into 2048 1-MHz channels. All four Stokes parameters were measured. This table was created by the HEASARC in August 2015 based on the union of <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/439/1212">CDS Catalog J/MNRAS/439/1212</a> files table2.dat (the 50 sources in the 3-hr field) and table3.dat (the 35 sources in the 21-hr field). This is a service provided by NASA HEASARC . 2014MNRAS.439.1212F https://heasarc.gsfc.nasa.gov/W3Browse/all/atcdfsss82.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=atcdfsss82& GET text/xml 180 99999 true 52.15208333 -28.69694444 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=atcdfsss82 GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_atcdfsss82&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0166666666666667 Radio public atcdfsss82 Australia Telescope Chandra Deep Field-South and SDSS Stripe 82 name Source Designation (AT20GDP JHHMMS+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_20_ghz Total Flux Density at 20 GHz mJy phot.flux.density;em.radio.12-30GHz double nullable flux_20_ghz_error RMS Uncertainty in Total Flux Density at 20 GHz mJy stat.error;phot.flux.density;em.radio.12-30GHz double nullable flux_1p4_ghz_limit Limit Flag for Best 1.4-GHz Flux Density meta.code;phot.flux.density;em.radio.750-1500MHz char nullable flux_1p4_ghz Best 1.4-GHz Flux Density mJy phot.flux.density;em.radio.750-1500MHz double nullable spectral_index_limit Limit Flag for Alpha meta.code;spect.index;em.radio char nullable spectral_index Spectral Index (Alpha) Between 1.4 and 20 GHz spect.index;em.radio double nullable spectral_class_flag Spectral Class: S=Steep, F=Flat, I=Inverted meta.code;spect.index;em.radio char nullable flux_1p4_ghz_flag Flag [I] Indicates Flux Densities Derived from NVSS or ATLAS/FIRST Image meta.code;phot.flux.density;em.radio.750-1500MHz char nullable alt_flux_1p4_ghz_limit Limit Flag for Total Flux Density at 1.4 GHz meta.code;phot.flux.density;em.radio.750-1500MHz char nullable nvss_flux_1p4_ghz_flag Flag [I] Indicates Flux Densities Derived from the NVSS Image meta.code;phot.flux.density;em.radio.750-1500MHz char nullable alt_flux_1p4_ghz_flag Flag [I] Indicates Flux Densities Derived from the ATLAS/FIRST Image meta.code;phot.flux.density;em.radio.750-1500MHz char nullable nvss_flux_1p4_ghz_limit Limit Flag for NVSS Total Flux Density at 1.4 GHz meta.code;phot.flux.density;em.radio.750-1500MHz char nullable source_id Catalog Source Identifier (SNN) meta.id;src char nullable bii Galactic Latitude degree pos.galactic.lat double nullable lii Galactic Longitude degree pos.galactic.lon double nullable alt_flux_1p4_ghz Total Flux Density at 1.4 GHz mJy phot.flux.density;em.radio.750-1500MHz double nullable nvss_flux_1p4_ghz NVSS Total Flux Density at 1.4 GHz mJy phot.flux.density;em.radio.750-1500MHz double 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