J/ApJ/718/587ivo://CDS.VizieR/J/ApJ/718/587doi:10.26093/cds/vizier.17180587CDSMahony E.K.Sadler E.M.Murphy T.Ekers R.D.Edwards P.G.Massardi M.2017-10-13T15:41:50Z2012-07-27T09:07:02ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiastronomical-object-identificationradio-continuum-emissiongamma-ray-astronomyThe high-frequency radio sky, like the gamma-ray sky surveyed by the Fermi satellite, is dominated by flat spectrum radio quasars and BL Lac objects at bright flux levels. To investigate the relationship between radio and gamma-ray emission in extragalactic sources, we have cross-matched the Australia Telescope 20 GHz survey catalog (AT20G) with the Fermi-LAT 1 year Point Source Catalog (1FGL). The 6.0sr of sky covered by both catalogs (DEC<0{deg},|b|>1.5{deg}) contains 5890 AT20G radio sources and 604 1FGL gamma-ray sources. The AT20G source positions are accurate to within ~1 arcsec and, after excluding known Galactic sources, 43% of Fermi 1FGL sources have an AT20G source within the 95% Fermi confidence ellipse. Monte Carlo tests imply that at least 95% of these matches are genuine associations. Only five gamma-ray sources (1% of the Fermi catalog) have more than one AT20G counterpart in the Fermi error box. The AT20G matches also generally support the active galactic nucleus (AGN) associations in the First LAT AGN Catalog. We find a trend of increasing gamma-ray flux density with 20GHz radio flux density. The Fermi detection rate of AT20G sources is close to 100% for the brightest 20GHz sources, decreasing to 20% at 1Jy, and to roughly 1% at 100mJy. Eight of the matched AT20G sources have no association listed in 1FGL and are presented here as potential gamma-ray AGNs for the first time. We also identify an alternative AGN counterpart to one 1FGL source. The percentage of Fermi sources with AT20G detections decreases toward the Galactic plane, suggesting that the 1FGL catalog contains at least 50 Galactic gamma-ray sources in the southern hemisphere that are yet to be identified.2010ApJ...718..587Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/718/587CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)J/A+A/535/A69 : AGN Fermi/LAT {gamma}-ray and 37GHz fluxes (Nieppola+, 2011)J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)J/MNRAS/402/2403 : Australia Telescope 20GHz Survey Catalog, AT20G (Murphy+,J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)J/ApJ/709/1407 : SED of the Fermi blazars (Li+, 2010)J/ApJ/706/L7 : The Fermi LAT sky as seen by INTEGRAL/IBIS (Ubertini+, 2009)J/ApJS/183/46 : Fermi/LAT bright gamma-ray source list (0FGL) (Abdo+, 2009)J/MNRAS/384/775 : Bright Source Sample of AT20G Survey (Massardi+, 2008)J/ApJS/175/97 : CGRaBS: survey of {gamma}-ray blazar candidates (Healey+,https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/718/587https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/718/587http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/718/587https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/718/587https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/718/587http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/718/587GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/718/587/table4 (The Fermi-AT20G catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/718/587/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/718/587/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/718/587/table4?GETtext/xml+votable180.050000true0.2-7.80.0055555555555555566/16655 16661 16676 16971 17048 17184 17347 17364 17414 17516 17541 17579 17611 17665 17927 17946 18457 18624 18661 18718 18758 19023 19088 20489 20657 20777 20836 20888 20920 20932 20935 21121 21160 21266 21358 21437 21564 21574 21626 21758 21768 21793 22558 22658 22730 22828 22849 22917 22950 23099 23121 24635 24775 24828 24845 24906 24941 25196 25302 25501 25525 25542 25630 25649 25677 25750 25818 25864 26131 26695 26798 26898 27207 28673 28736 29016 29017 29072 29743 29772 29844 29991 30015 32809 32832 33040 33549 33560 33570 33611 33658 33774 33825 33827 33920 34013 34086 34123 34209 34264 34317 34461 34517 34528 34572 34637 34675 34747 34870 35079 35119 35252 35281 35370 35475 35501 35700 35706 35722 35786 35801 36059 36090 36100 36111 36151 36188 36296 36551 36554 36665 36708 36882 36933 36941 37040 37045 37215 37313 37379 37512 37529 37686 37779 37995 38261 38355 38937 39077 39658 39963 39974 40096 40174 40479 40703 40762 40766 40874 40949 41072 41110 41335 41363 41426 41460 41524 41619 41725 41948 42188 42515 42571 42609 42822 42901 42914 42980 43036 43066 43085 43116 43122 43233 43246 43262 43366 43380 43412 43451 43822 44059 44069 44147 44245 44313 44669 44730 44908 45011 45081 45480 45713 45836 46066 46204 46251 46369 46374 46626 46723 46740 46835 46852 46963 46964 47014 47057 47080 47248 47375 47391 47419 47512 47708 47714 47969 48023 48123 48300 48595 48798 490716.62606957030801e-25 1.325213914061602e-23https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/718/587?format=asciiGamma-rayRadiodefaultJ/ApJ/718/587/table4The Fermi-AT20G catalogr_zReference for zmeta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint1FGLFermi-LAT name (JHHMM.m+DDMM)meta.id;meta.maincharRAJ2000Fermi Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Fermi Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainamajThe 95% confidence semi-major axisdegphys.angSize.smajAxisfloataminThe 95% confidence semi-minor axisdegphys.angSize.sminAxisfloatPA[-90/90] The 95% confidence position angledegpos.posAngfloatEpivPivot energy (1)MeVphys.energyfloatFluxDifferential Gamma-ray flux density at PEngcm**-2.MeV**-1.s**-1phot.flux.density;em.gamma.harddoublee_FluxUncertainty in Fluxcm**-2.MeV**-1.s**-1stat.error;phot.fluxdoubleVarGamma-ray variability index (2)src.var.indexfloat0FGLFermi Bright Source ID (JHHMM.m+DDMM)meta.id.crosscharAssocFermi association in 1FGLmeta.id.assoccharClassClassification in 1FGL (3)meta.code.classcharAT20GAT20G name (JHHMMSS+DDMMSS)meta.id.crosscharRAAAT20G Hour of Right Ascension (J2000)pos.eq.raDEAAT20G Degree of Declination (J2000)pos.eq.decGLONAT20G Galactic longitudedegpos.galactic.lonGLATAT20G Galactic latitudedegpos.galactic.latfloatOffOffset between Fermi and AT20G positionsdegpos;arith.difffloatS20Flux density at 20GHzmJyphot.flux.density;em.radio.12-30GHzintS8.4? Flux density at 8.4GHzmJyphot.flux.density;em.radio.6-12GHzintnullableS4.8? Flux density at 4.8GHzmJyphot.flux.density;em.radio.3-6GHzintnullablealpha? Spectral index between 4.8 and 20GHzspect.index;em.radio.12-30GHzfloatnullableQ[p/g] AT20G flux quality flag (4)meta.code.qual;phot.fluxcharS1? Flux density at 1GHz (5)mJyphot.flux.density;em.radio.750-1500MHzintnullableRAO? Optical Hour of Right Ascension (J2000)pos.eq.ranullableDEO? Optical Degree of Declination (J2000)pos.eq.decnullableBmag? SuperCOSMOS B_J_ band magnitudemagphot.mag;em.opt.Bfloatnullablez? Redshiftsrc.redshiftfloatnullableSimbadSimbad column added by the CDSmeta.refcharNEDSimbad column added by the CDSmeta.refchar