J/MNRAS/439/1212ivo://CDS.VizieR/J/MNRAS/439/1212doi:10.26093/cds/vizier.74391212CDSFranzen T.M.O.Sadler E.M.Chhetri R.Ekers R.D.Mahony E.K.,Murphy T.Norris R.P.Waldram E.M.Whittam I.H.2024-08-08T20:12:37Z2015-03-12T16:09:11ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsurveysradio-sourcesWe present a source catalogue and first results from a deep, blind radio survey carried out at 20GHz with the Australia Telescope Compact Array, with follow-up observations at 5.5, 9 and 18GHz. The Australia Telescope 20GHz (AT20G) deep pilot survey covers a total area of 5deg^2^ in the Chandra Deep Field South and in Stripe 82 of the Sloan Digital Sky Survey. We estimate the survey to be 90% complete above 2.5mJy. Of the 85 sources detected, 55percent have steep spectra ({alpha}_1.4_^20^<-0.5) and 45% have flat or inverted spectra ({alpha}_1.4_^20^>=-0.5). The steep-spectrum sources tend to have single power-law spectra between 1.4 and 18GHz, while the spectral indices of the flat- or inverted-spectrum sources tend to steepen with frequency. Among the 18 inverted-spectrum ({alpha}_1.4_^20^>=0.0) sources, 10 have clearly defined peaks in their spectra with {alpha}_1.4_^5.5^>0.15 and {alpha}_9_^18^<-0.15. On a 3-yr time-scale, at least 10 sources varied by more than 15percent at 20GHz, showing that variability is still common at the low flux densities probed by the AT20G-deep pilot survey.2014MNRAS.439.1212Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/439/1212CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)J/AJ/132/2409 : Deep ATLAS radio observations of CDFS (Norris+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/439/1212https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/439/1212http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/439/1212https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/439/1212https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/439/1212http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/439/1212GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/439/1212/AT20GDP (The 20-GHz source catalogue for the 03 and 21hr fields)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/439/1212/AT20GDP?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/439/1212/AT20GDP?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/439/1212/AT20GDP?GETtext/xml+votable180.050000true51.52375-27.7930560.0055555555555555565/8983 6/19089-19091 19094 19097 35953 35956-359589.276497240453405e-25 1.325213914061602e-23https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/439/1212?format=asciiRadiodefaultJ/MNRAS/439/1212/AT20GDPThe 20-GHz source catalogue for the 03 and 21hr fieldsl_S1.4Limit flag on S1.4meta.code.errorcharSeqSource number (SNN)meta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAT20GDPSource name (JHHMMS+DDMMSS)meta.id;meta.maincharRAJ2000Right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)pos.eq.dec;meta.mainS20Total flux density at 20GHz (2)mJyphot.flux.density;em.radio.12-30GHzfloate_S20rms uncertainty on S20 (3)mJystat.errorfloatl_S1.4NLimit flag on S1.4Nmeta.code.errorcharS1.4N? Total flux density at 1.4GHz taken from the NVSS catalogue (Cat. VIII/65) or estimated from the NVSS image (4)mJyphot.flux.density;em.radio.750-1500MHzfloatnullablen_S1.4N[*] * indicates flux densities derived from the NVSS imagemeta.notecharl_S1.4ALimit flag on S1.4Ameta.code.errorcharS1.4ATotal flux density at 1.4GHz taken from the ATLAS/FIRST (J/AJ/132/2409 or VIII/90) catalogues or estimated from the ATLAS/FIRST image in the case of the 03hr/21hr field (5)mJyphot.flux.density;em.radio.750-1500MHzfloatn_S1.4A[*] * indicates flux densities derived from the ATLAS/FIRST imagemeta.notecharS1.4'best' 1.4-GHz flux density, S1.4 (6)mJyphot.flux.density;em.radio.750-1500MHzfloatn_S1.4[*] * indicates flux densities derived from NVSS or ATLAS/FIRST imagemeta.notecharl_alphaLimit flag on alphameta.code.error;pos.eq.racharalphaSpectral index {alpha}^1.4^_20_ between 1.4 and 20GHz obtained using S1.4 and S20spect.index;em.radio.12-30GHzfloatClSpectral class: S=steep, F=flat, I=invertedsrc.classcharSEDPlot the spectrum with SPECFIND (Vollmer et al. 2009, Cat. VIII/85)meta.ref.urlcharNVSSDisplay the NVSS (Condon et al., 1988, Cat. VIII/65) source(s) within 27"meta.ref.urlintnullableATLASDisplay the ATLAS data (Norris et al., 2006, Cat. J/AJ/132/2409) datameta.ref.urlchar