J/ApJ/768/105ivo://CDS.VizieR/J/ApJ/768/105doi:10.26093/cds/vizier.17680105CDSMcGreer I.D.Jiang L.Fan X.Richards G.T.Strauss M.A.Ross N.P.,White M.Shen Y.Schneider D.P.Myers A.D.Brandt W.N.Degraf C.,Glikman E.Ge J.Streblyanska A.2015-01-16T09:57:35Z2015-01-07T13:56:11ZCDS support team

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

cds-question@unistra.frquasarsredshiftedspectroscopyvisible-astronomysloan-photometryinfrared-photometryWe present a measurement of the Type I quasar luminosity function at z=5 using a large sample of spectroscopically confirmed quasars selected from optical imaging data. We measure the bright end (M_1450_<-26) with Sloan Digital Sky Survey (SDSS) data covering ~6000deg^2^, then extend to lower luminosities (M_1450_<-24) with newly discovered, faint z~5 quasars selected from 235deg^2^ of deep, coadded imaging in the SDSS Stripe 82 region (the celestial equator in the Southern Galactic Cap). The faint sample includes 14 quasars with spectra obtained as ancillary science targets in the SDSS-III Baryon Oscillation Spectroscopic Survey, and 59 quasars observed at the MMT and Magellan telescopes. We construct a well-defined sample of 4.7<z<5.1 quasars that is highly complete, with 73 spectroscopic identifications out of 92 candidates. Our color selection method is also highly efficient: of the 73 spectra obtained, 71 are high-redshift quasars. These observations reach below the break in the luminosity function (M_1450_^*^~-27). The bright-end slope is steep ({beta}<~-4), with a constraint of {beta}<-3.1 at 95% confidence. The break luminosity appears to evolve strongly at high redshift, providing an explanation for the flattening of the bright-end slope reported previously. We find a factor of ~2 greater decrease in the number density of luminous quasars (M_1450_<-26) from z=5 to z=6 than from z=4 to z=5, suggesting a more rapid decline in quasar activity at high redshift than found in previous surveys. Our model for the quasar luminosity function predicts that quasars generate ~30% of the ionizing photons required to keep hydrogen in the universe ionized at z=5.2013ApJ...768..105Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/768/105CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012)J/ApJ/746/169 : Luminosity function of broad-line quasars (Shen+, 2012)J/ApJ/743/125 : Likelihood method for QSOs selection (Kirkpatrick+, 2011)J/ApJ/728/23 : GALEX UV-bright high-redshift quasars (Worseck+, 2011)J/A+A/525/A37 : QSO variability indexes in SDSS Stripe 82 (Meusinger+, 2011)J/ApJ/710/1498 : QSO luminosity function at z~4 (Glikman+, 2010)J/ApJ/699/782 : High-redshift SDSS-DR5 QSOs (Diamond-Stanic+, 2009)J/ApJ/693/8 : High-redshift QSOs in the COSMOS survey (Brusa+, 2009)J/ApJ/675/49 : High-redshift QSOs in the SWIRE survey (Siana+, 2008)J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)J/ApJ/633/630 : Low-mass stars found in CFHTLS (Willott+, 2005)J/AJ/125/1711 : Broad Absorption Line Quasars from SDSS (Reichard+, 2003)J/AJ/121/2308 : Sloan Digital Sky Survey quasar photometry (Richards+, 2001)J/AJ/121/31 : High-redshift quasars in SDSS (Fan+, 2001)http://www.sdss3.org/ : SDSS-III home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/768/105https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/768/105http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/768/105https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/768/105https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/768/105http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/768/105GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/768/105/table2 (Stripe 82 high-redshift quasar catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/768/105/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/768/105/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/768/105/table2?GETtext/xml+votable180.050000true309.990750.75538890.0055555555555555566/17663 17742 17749 17756 17757 17767 17770 17805 17809 17812 17813 17816 17817 17997 18005 18006 18009 18010 18018 18028 18063 18076 18077 18084 18088 18091 18685 18686 18766 18770 18779 18780 18787 18789 18791 18792 18833 18836 18839 18855 18857 18859 18860 18862 18882 19025 19027 19028 19030 19032 19033 19034 19036 19046 19048 19049 19093 19099 19109 19110 19111 19116 23103 23147 23181 23191 23193 23194 23203 23210 23216 30035 30039 300651.489977759996881e-19 4.653515163505597e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/768/105?format=asciiOpticalInfrareddefaultJ/ApJ/768/105/table2Stripe 82 high-redshift quasar catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.maingmag[22.6/26.7]? SDSS g-band AB magnitude (1)magphot.mag;em.opt.Bfloatnullablee_gmag[0.02/1]? gmag uncertaintymagstat.error;phot.mag;em.opt.Bfloatnullablermag[20.4/25.5] SDSS r-band AB magnitude (1)magphot.mag;em.opt.Rfloate_rmag[0/0.5] rmag uncertaintymagstat.error;phot.mag;em.opt.Rfloatimag[18.9/23.1] SDSS i-band AB magnitude (1)magphot.mag;em.opt.Ifloate_imag[0/0.07] imag uncertaintymagstat.error;phot.mag;em.opt.Ifloatzmag[18.7/22.2] SDSS z-band AB magnitude (1)magphot.mag;em.opt.Ifloate_zmag[0.01/0.2] zmag uncertaintymagstat.error;phot.mag;em.opt.IfloatJmag[18.8/22.1]? UKIDSS J-band AB magnitude (1)magphot.mag;em.IR.Jfloatnullablee_Jmag[0.05/0.9]? Jmag uncertaintymagstat.error;phot.mag;em.IR.Jfloatnullablef_Jmag[ce] c: J magnitude from MMT/SWIRC; e: lack of coveragemeta.codecharM1450[-28/-23] Monochromatic luminosity at rest-frame 1450{AA}magphys.magAbsfloatz[4.3/5.9] Redshiftsrc.redshiftfloatProb[0/1]? Selection probability p(M,z) of spectroscopically confirming this object (2)stat.probabilityfloatnullableNotesNotes (3)meta.notecharSDSSIAU SDSS-DR7 namemeta.id;meta.maincharSloanDisplay the online SDSS data for this quasarmeta.ref.urlcharSpInteractive spectrum from SDSSmeta.ref.urlchar