J/MNRAS/471/210ivo://CDS.VizieR/J/MNRAS/471/210doi:10.26093/cds/vizier.74710210CDSGuidetti D.Bondi M.Prandoni I.Muxlow T.W.B.Beswick R.Wrigley N.,Smail I.Mchardy I.Thomson A.P.Radcliffe J.Argo M.K.2024-08-17T20:20:18Z2020-07-03T14:20:30ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiradio-sourcesredshiftedgalaxy-classification-systemsWe present new observations of the GOODS-N field obtained at 5.5GHz with the Karl G. Jansky Very Large Array. The central region of the field was imaged to a median rms of 3{mu}Jy/beam with a resolution of 0.5 arcsec. From a 14-arcmin diameter region, we extracted a sample of 94 radio sources with signal-to-noise ratio greater than 5. Near-IR identifications are available for about ~88 per cent of the radio sources. We used different multiband diagnostics to separate active galactic nuclei (AGNs), both radiatively efficient and inefficient, from star-forming galaxies. From our analysis, we find that about 80 per cent of our radio-selected sample is AGN dominated, with the fraction rising to 92 per cent when considering only the radio sources with redshift >1.5. This large fraction of AGN-dominated radio sources at very low flux densities (the median flux density at 5.5GHz is 42{mu}Jy), where star-forming galaxies are expected to dominate, is somewhat surprising and at odds with other results. Our interpretation is that both the frequency and angular resolution of our radio observations strongly select against radio sources whose brightness distribution is diffuse on a scale of several kpc. Indeed, we find that the median angular sizes of the AGN-dominated sources is around 0.2-0.3arcsec against 0.8 arcsec for star-forming galaxies. This highlights the key role that high frequency radio observations can play in pinpointing AGN-driven radio emission at {mu}Jy levels. This work is part of the eMERGE legacy project.2017MNRAS.471..210Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/471/210CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/689/687 : GOODS-N spectroscopic survey (Barger+, 2008)J/ApJS/235/34 : Deep JVLA imaging of GOODS-N at 20cm (Owen, 2018)J/A+A/619/A48 : GOODS-N AGN VLBI detect. & radio properties (Radcliffe+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/471/210https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/471/210http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/471/210https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/471/210https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/471/210http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/471/210GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/471/210/table1 (The catalogue of source detected above 5 sigma at 5.5GHz)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/471/210/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/471/210/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/471/210/table1?GETtext/xml+votable180.050000true188.991416762.26023060.0055555555555555566/112523.313034785154005e-24 3.313034785154005e-24https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/471/210?format=asciiOpticalRadiodefaultJ/MNRAS/471/210/table1The catalogue of source detected above 5 sigma at 5.5GHzrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_NamePolarized (table 2) or Multiwavelength classification (table4) datameta.ref.urlcharNameSource name (JHHMMSS+DDMMSS)meta.id;meta.maincharprimaryRAJ2000Right ascension (J2000)pos.eq.ra;meta.maine_RAJ2000Error on RA (arcsec)arcsecstat.error;pos.eq.rafloatDEJ2000Declination (J2000)pos.eq.dec;meta.maine_DEJ2000Error on DE (arcsec)arcsecstat.error;pos.eq.decfloatS/NSignal-to-noise ratiostat.snrfloatFpeakPeak brightness at 5GHzuJy/beamphot.flux.density;em.radio.3-6GHzfloate_FpeakError on peak brightness at 5GHzuJy/beamstat.errorfloatFtotTotal flux density at 5GHzuJyphot.flux.density;em.radio.3-6GHzfloate_FtotError on total flux density at 5GHzuJystat.errorfloatAmaj? Deconvolved sizes: major axisarcsecphys.angSize.smajAxisfloatnullableBmin? Deconvolved sizes: minor axisarcsecphys.angSize.sminAxisfloatnullablePA? Deconvolved sizes: position angledegpos.distance;pos.posAngintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/471/210/table2Polarized sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (JHHMMSS+DDMMSS)meta.id;meta.maincharPpeakPeak of polarized emission at 5GHzuJyphot.flux.density;em.radio.3-6GHzfloatSNRPSNR of the polarized emissionstat.snrfloatPtotTotal polarized emission at 5GHzuJyphot.flux.density;em.radio.3-6GHzfloatPolAverage fractional polarization at 5GHz%phys.polarization;em.radio.3-6GHz;stat.meanfloatJ/MNRAS/471/210/table4Multiwavelength classification for the 5.5GHz sources with NIR identificationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (JHHMMSS+DDMMSS)meta.id;meta.maincharzz Spectroscopic (s) or photometric (p) redshiftsrc.redshiftfloatn_z[s/p] Spectroscopic (s) or photometric (p) redshiftmeta.notecharClassIRClassification based on the four IR diagnoticsmeta.code.classcharX-ray[Y/N] X-ray AGN (Y) or not (N)meta.codecharRadio-exc[Y/N] Radio-excess AGN (Y) or not (N)meta.codecharVLBI[Y/N] VLBI detected sources (Y) or not (N)meta.codecharClassFinal classification combining all the multiwavelength diagnosticsmeta.code.classchar