J/ApJ/723/737ivo://CDS.VizieR/J/ApJ/723/737doi:10.26093/cds/vizier.17230737CDSVillforth C.Koekemoer A.M.Grogin N.A.2011-01-25T15:24:06Z2010-11-09T16:14:04ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiquasarsphotometryredshiftedVariability is a property shared by practically all active galactic nuclei (AGNs). This makes variability selection a possible technique for identifying AGNs. Given that variability selection makes no prior assumption about spectral properties, it is a powerful technique for detecting both low-luminosity AGNs in which the host galaxy emission is dominating and AGNs with unusual spectral properties. In this paper, we will discuss and test different statistical methods for the detection of variability in sparsely sampled data that allow full control over the false positive rates. We will apply these methods to the GOODS North and South fields and present a catalog of variable sources in the z band in both GOODS fields. Out of the 11 931 objects checked, we find 155 variable sources at a significance level of 99.9%, corresponding to about 1.3% of all objects. After rejection of stars and supernovae, 139 variability-selected AGNs remain. Their magnitudes reach down as faint as 25.5mag in z. Spectroscopic redshifts are available for 22 of the variability-selected AGNs, ranging from 0.046 to 3.7. The absolute magnitudes in the rest-frame z band range from ~-18 to -24, reaching substantially fainter than the typical luminosities probed by traditional X-ray and spectroscopic AGN selection in these fields. Therefore, this is a powerful technique for future exploration of the evolution of the faint end of the AGN luminosity function up to high redshifts.2010ApJ...723..737Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/723/737CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/261 : GOODS initial results (Giavalisco+, 2004)J/ApJ/640/603 : Catalog of AGNs in the GOODS fields (Treister+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/723/737https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/723/737http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/723/737https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/723/737https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/723/737http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/723/737GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/723/737/table5 (Basic properties of variability selected AGNs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/723/737/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/723/737/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/723/737/table5?GETtext/xml+votable180.050000true53.01248-27.703787220.0055555555555555566/11252 35935https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/723/737?format=asciiOpticaldefaultJ/ApJ/723/737/table5Basic properties of variability selected AGNsr_CommentReference for Comment (4)meta.ref;pos.framecharz? Spectroscopic redshiftsrc.redshiftfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGOODSGOODS ID (JHHMMSS.ss+DDMMSS.s, J2000)meta.id;meta.maincharn_GOODSObject detected in other studies (1)meta.notecharzmagMagnitude in F850LP bandmagphot.mag;em.opt.IfloatStel[0/1] Stellarity Measure ClassStar from Sextractor (1 is point like, 0 is extended)src.class.starGalaxyfloatCC-Statistics (2)stat.fit.goodnessfloatVarVariability Strength%stat.fit.goodness;src.varfloatDetDetection significance (3)stat.fit.goodnesscharCommentDescription of Morphology or Identification as Starsrc.morphcharq_z[LSTN] Quality of redshift (5)meta.code.qual;src.redshiftcharr_z[fj] Redshift reference if not Popesso et al. (2009A&A...494..443P) (6)meta.ref;pos.framecharzMAG? Absolute magnitude in restframe F850LP band only if redshift knownmagsrc.redshiftfloatnullableRAJ2000Right ascension in decimal degrees (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000.0)degpos.eq.dec;meta.main