J/ApJ/405/498ivo://CDS.VizieR/J/ApJ/405/498doi:10.26093/cds/vizier.14050498CDSWINDHORST R.A.FOMALONT E.B.PARTRIDGE R.B.LOWENTHAL J.D.2013-03-05T06:34:13Z1997-12-09T20:48:06ZCDS support team

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

cds-question@unistra.frradio-sourcesWe used the VLA to make deep images of two 7x7' fields at 8.44 GHz with 10" resolution. With an rms noise of 3.2 and 5.1 {micro}Jy, respectively, in the two fields, we compiled a catalog of 82 sources. The normalized differential 8.44 GHz counts are similar to those at 1.41 and 4.86 GHz. All show a similarly steep submillijansky slope, which is only somewhat flatter than that expected for a nonevolving Euclidean population ({gamma}=2.5). Microjansky radio sources at 4.86 GHz have been identified with faint blue galaxies (18<~V<~28 mag). We argue that their expected median redshift is about 0.5-0.75. Hence, cosmological evolution may be needed to explain the steep slope of the microjansky counts. The 8.44 GHz counts must converge with slope {gamma}<2.0 below S(8.44)~300 nJy, or they would exceed the available field galaxy counts down to V~28 mag, and they must permanently converge below S(8.44)~20 nJy, or their integrated sky brightness would distort the observed thermal cosmic background radiation spectrum at centimeter wavelengths. The estimated 31.5 GHz sky brightness from nanojansky to jansky levels is <36 {micro}K (3{sigma}). Even if weak radio sources cluster on scales of degrees as faint galaxies do, their anisotropic contribution to the COBE DMR experiment (with 7deg FWHM-beam) would not exceed ~1.2{micro}K.1993ApJ...405..498Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/405/498CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/405/498https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/405/498http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/405/498https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/405/498https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/405/498http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/405/498GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/405/498/table1b (Catalog of 8.44 GHz Radio Sources in the Cepheus Field)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/405/498/table1b?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/405/498/table1b?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/405/498/table1b?GETtext/xml+votable180.050000true48.562403580.24465310.005555555555555556Cone search capability for table J/ApJ/405/498/table1a (Catalog of 8.44 GHz Radio Sources in the Linx.2 Field)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/405/498/table1a?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/405/498/table1a?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/405/498/table1a?GETtext/xml+votable180.050000true131.060640344.58358740.0055555555555555566/4033 4036 65175.5924024392990166e-24 5.5924024392990166e-24https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/405/498?format=asciiRadiodefaultJ/ApJ/405/498/table1bCatalog of 8.44 GHz Radio Sources in the Cepheus Fielde_RA1950One sigma error on right ascensionsstat.error;pos.eq.rafloatDE1950Declination (1950)pos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharn_Name[*] Source with an asterisk is not in the complete samplemeta.notecharRA1950Right ascension (1950)pos.eq.ra;meta.maine_DE1950One sigma error on declinationarcsecstat.error;pos.eq.decfloatS8.44Integrated sky flux density at 8.44GHzuJyphot.flux.density;em.radio.6-12GHzfloate_S8.44One sigma error on integrated sky flux densityuJystat.errorfloatl_SizeM[<] When '<' the source is an unresolved source and it's given the 1.5{sigma} upper limit on the Gaussian major axismeta.code.error;pos.distance;phys.sizecharSizeMDeconvolved Gaussian source size (FWHM): major axisarcsecphys.angSizefloate_SizeM[]? Error on major axisarcsecstat.error;pos.distance;phys.sizefloatnullableSizem[]? Deconvolved Gaussian source size (FWHM): minor axisarcsecphys.angSizefloatnullablee_Sizem[]? Error on minor axisarcsecstat.error;pos.distance;phys.sizefloatnullablePA[]? Position angle of major axisdegpos.posAngintnullablee_PA[]? Error on position angledegstat.errorintnullableWeightSource weight in the 8.44 GHz countsstat.weightfloatS(p)Measured peak flux density on the 10arcsec resolution imageuJyphot.flux.density;em.radio.6-12GHzfloate_S(p)One sigma error on measured peak flux densityuJystat.errorfloatS(int)Resulting integrated flux density on the 10 arcsec imageuJyphot.flux.density;em.radio.6-12GHzfloate_S(int)One sigma error on resulting integrated flux densityuJystat.errorfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexedJ/ApJ/405/498/table1aCatalog of 8.44 GHz Radio Sources in the Linx.2 FieldrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharn_Name[*] Source with an asterisk is not in the complete samplemeta.notecharRA1950Right ascension (1950)pos.eq.ra;meta.maine_RA1950One sigma error on right ascensionsstat.error;pos.eq.rafloatDE1950Declination (1950)pos.eq.dec;meta.maine_DE1950One sigma error on declinationarcsecstat.error;pos.eq.decfloatS8.44Integrated sky flux density at 8.44GHzuJyphot.flux.density;em.radio.6-12GHzfloate_S8.44One sigma error on integrated sky flux densityuJystat.errorfloatl_SizeM[<] When '<' the source is an unresolved source and it's given the 1.5{sigma} upper limit on the Gaussian major axismeta.code.error;pos.distance;phys.sizecharSizeMDeconvolved Gaussian source size (FWHM): major axisarcsecphys.angSizefloate_SizeM[]? Error on major axisarcsecstat.error;pos.distance;phys.sizefloatnullableSizem[]? Deconvolved Gaussian source size (FWHM): minor axisarcsecphys.angSizefloatnullablee_Sizem[]? Error on minor axisarcsecstat.error;pos.distance;phys.sizefloatnullablePA[]? Position angle of major axisdegpos.posAngintnullablee_PA[]? Error on position angledegstat.errorintnullableWeightSource weight in the 8.44 GHz countsstat.weightfloatS(p)Measured peak flux density on the 10arcsec resolution imageuJyphot.flux.density;em.radio.6-12GHzfloate_S(p)One sigma error on measured peak flux densityuJystat.errorfloatS(int)Resulting integrated flux density on the 10 arcsec imageuJyphot.flux.density;em.radio.6-12GHzfloate_S(int)One sigma error on resulting integrated flux densityuJystat.errorfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexed