J/ApJ/778/127ivo://CDS.VizieR/J/ApJ/778/127doi:10.26093/cds/vizier.17780127CDSGlikman E.Urrutia T.Lacy M.Djorgovski S.G.Urry M.Croom S.,Schneider D.P.Mahabal A.Graham M.Ge J.2017-08-29T14:57:43Z2015-06-08T09:15:50ZCDS support team

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

cds-question@unistra.frquasarsredshiftedinfrared-photometryradio-sourcesvisible-astronomysloan-photometryinterstellar-reddeningsurveysWe present the results of a pilot survey to find dust-reddened quasars by matching the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio catalog to the UKIDSS near-infrared survey and using optical data from Sloan Digital Sky Survey to select objects with very red colors. The deep K-band limit provided by UKIDSS allows for finding more heavily reddened quasars at higher redshifts as compared with previous work using FIRST and Two Micron All Sky Survey (2MASS). We selected 87 candidates with K<=17.0 from the UKIDSS Large Area Survey (LAS) First Data Release (DR1), which covers 190deg^2^. These candidates reach up to ~1.5mag below the 2MASS limit and obey the color criteria developed to identify dust-reddened quasars. We have obtained 61 spectroscopic observations in the optical and/or near-infrared, as well as classifications in the literature, and have identified 14 reddened quasars with E(B-V)>0.1, including 3 at z>2. We study the infrared properties of the sample using photometry from the Wide-Field Infrared Survey Explorer and find that infrared colors improve the efficiency of red quasar selection, removing many contaminants in an infrared-to-optical color-selected sample alone. The highest-redshift quasars (z>~2) are only moderately reddened, with E(B-V)~0.2-0.3. We find that the surface density of red quasars rises sharply with faintness, comprising up to 17% of blue quasars at the same apparent K-band flux limit. We estimate that to reach more heavily reddened quasars (i.e., E(B-V)>~0.5) at z>2 and a depth of K=17, we would need to survey at least ~2.5 times more area.2013ApJ...778..127Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/778/127CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/ApJ/772/26 : AGN with WISE. II. The NDWFS Bootes field (Assef+, 2013)J/ApJ/757/51 : FIRST-2MASS dust-reddened QSO spectra (Glikman+, 2012)J/MNRAS/424/2876 : Large area KX quasar catalogue (Maddox+, 2012)J/AJ/144/49 : Quasars from SDSS-DR7, WISE and UKIDSS surveys (Wu+, 2012)J/AJ/141/105 : NIR-matched quasar catalog (Peth+, 2011)J/ApJ/710/1498 : QSO luminosity function at z~4 (Glikman+, 2010)J/MNRAS/401/1429 : WiggleZ dark energy survey (DR1) (Drinkwater+, 2010)J/ApJ/698/1095 : The FIRST-2MASS red QSO survey. II. (Urrutia+, 2009)J/ApJS/181/233 : Catalog of merging galaxies (Hwang+, 2009)J/ApJ/680/130 : Mid-IR colors of AGNs in the MUSYC ECDF-S (Cardamone+, 2008)J/MNRAS/386/1605 : Luminous K-band selected QSOs from UKIDSS (Maddox+, 2008)J/MNRAS/383/1513 : 2MASS, SDSS and FIRST fluxes of QSOs (Labita+, 2008)J/ApJ/667/673 : FIRST-2MASS red quasar survey (Glikman+, 2007)J/ApJ/666/806 : SED of Spitzer quasars (QUEST) (Netzer+, 2007)J/ApJ/663/81 : SED of hard X-ray selected AGN in XMDS (Polletta+, 2007)J/AJ/133/186 : Optical spectroscopy of luminous AGNs and QSOs (Lacy+, 2007)J/MNRAS/372/425 : 2dF-SDSS Luminous Red Galaxy Survey, 2SLAQ (Cannon+, 2006)J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)J/ApJ/642/673 : IR-selected obscured AGN candidates (Polletta+, 2006)J/ApJ/640/579 : Near-infrared spectra of 27 SDSS quasars (Glikman+, 2006)J/ApJS/158/161 : Photometric redshift catalog from the RCS (Hsieh+, 2005)J/ApJ/607/60 : FIRST-2MASS faint sources (Glikman+, 2004)J/ApJS/135/227 : The FIRST bright quasar survey. III. (Becker+, 2001)J/ApJS/126/133 : The FIRST bright quasar survey. II. (White+, 2000)J/AJ/112/407 : The FIRST bright QSO survey (Gregg+, 1996)J/ApJ/269/352 : Quasar evolution (Schmidt+, 1983)http://www.sdss.org/ : SDSS home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/778/127https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/778/127http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/778/127https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/778/127https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/778/127http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/778/127GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/778/127/table1 (UKFS (UKIDSS+FIRST+SDSS) red quasar candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/778/127/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/778/127/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/778/127/table1?GETtext/xml+votable180.050000true3.1779167-0.75411110.005555555555555556Cone search capability for table J/ApJ/778/127/table2 (Reddening properties of UKFS red quasars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/778/127/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/778/127/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/778/127/table2?GETtext/xml+votable180.050000true25.37929171.01702780.0055555555555555565/4458 6/0 1 4126 4224 17725 17727 17747 17750 17766 17767 17769 17770 17772 17774 17805 17809 17811 17812 17813 17817 17818 17819 17836 17837 17840 17856 17858 18007 18013 18065 18069 18075 18083 18084 18096 18767 18778 18789 18851 18852 18853 18854 18862 18864 19025 19028 19200 21836 21974 21975 21978 21979 26006 26021 26201 26204 26214 27167 27185 27188 27190 27195 27196 27210 27268 27377 27536 31468 31472 314749.276497240453405e-25 3.5010283109654867e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/778/127?format=asciiInfraredRadioOpticaldefaultJ/ApJ/778/127/table1UKFS (UKIDSS+FIRST+SDSS) red quasar candidatesUKFSmeta.id;meta.maincharprimaryl_rmagLimit flag on rmagmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRedNumber of redenning data for this red QSO (table 2)meta.ref.urlintnullableRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainrmag[20/24] SDSS r band AB magnitudemagphot.mag;em.opt.Rfloatl_imagLimit flag on imagmeta.code.errorcharimag[19.5/24.5] SDSS i band AB magnitudemagphot.mag;em.opt.Ifloatl_YmagLimit flag on Ymagmeta.code.error;pos.cartesian.ycharYmag[17.6/20.5] UKIDSS Y band magnitudemagphot.mag;em.IR.Jfloatl_JmagLimit flag on Jmagmeta.code.errorcharJmag[16.5/19.6] UKIDSS J band magnitudemagphot.mag;em.IR.Jfloatl_HmagLimit flag on Hmagmeta.code.errorcharHmag[15/19] UKIDSS H band magnitudemagphot.mag;em.IR.HfloatKmag[13.5/17] UKIDSS K band magnitudemagphot.mag;em.IR.Kfloatl_J-KLimit flag on J-Kmeta.code.error;phot.color;em.IR.JcharJ-K[1.5/3.5] The (J-K) color indexmagphot.color;em.IR.J;em.IR.Kfloatl_r-KLimit flag on r-Kmeta.code.errorcharr-K[5/8] The (r-K) color indexmagphot.color;em.opt.R;em.IR.KfloatS20[1/863] FIRST 20cm (1.4GHz) flux densitymJyphot.flux.density;em.radio.750-1500MHzfloatNIR? Near-IR spectroscopy reference (1)meta.bibintnullableOptOptical spectroscopy reference (2)meta.bibcharClassSource classification: Galaxy, QSO or NLAGN (narrow-lines AGN)src.classcharz[0.2/2.6]? Redshift (spectroscopic, unless "photz" specified in comment)src.redshiftfloatnullableComAdditional comment (3)meta.notecharUKIDSSDisplay the UKIDSS-DR9 LAS data (II/319) within 1"meta.ref.urlcharDR7Display the SDSS-DR7 photometric catalog (II/294) within 1"meta.ref.urlcharFIRSTDisplay the FIRST data (VIII/90) within 2"meta.ref.urlcharSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/778/127/table2Reddening properties of UKFS red quasarsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintUKFSUKFS designation (HHMM+DDMM; J2000)meta.idcharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainz[0.2/2.6] Redsfhitsrc.redshiftfloatKsmag[13.5/17] Ks-band magnitudemagphot.mag;em.IR.KfloatE(B-V)pE(B-V) photometricmagphot.color.excessfloatf_E(B-V)p[a] Value based on 2-component quasar (1)meta.codecharE(B-V)o[0.15/1.07]? Optical E(B-V)magphot.color.excessfloatnullableE(B-V)i[-0.34/1.5]? Near-IR E(B-V)magphot.color.excessfloatnullableE(B-V)c[0.3/0.89]? Combined E(B-V)magphot.color.excessfloatnullableKMag0[-32/-24] De-reddened absolute K-band magnitudemagphys.magAbsfloatf_KMag0[a] Value based on 2-component quasar (1)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlchar