J/ApJS/190/77ivo://CDS.VizieR/J/ApJS/190/77doi:10.26093/cds/vizier.21900077CDSKilic M.Leggett S.K.Tremblay P.-E.Von Hippel T.Bergeron P.,Harris H.C.Munn J.A.Williams K.A.Gates E.Farihi J.2017-10-11T05:13:04Z2010-11-17T17:05:47ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsinfrared-photometryvisible-astronomyWide-band photometrystellar-spectral-typessurveysWe present optical spectroscopy and near-infrared photometry of 126 cool white dwarfs (WDs) in the Sloan Digital Sky Survey (SDSS DR3). Our sample includes high proper motion targets selected using the SDSS and USNO-B astrometry and a dozen previously known ultracool WD candidates. Our optical spectroscopic observations demonstrate that a clean selection of large samples of cool WDs in the SDSS (and the SkyMapper, Pan-STARRS, and the Large Synoptic Survey Telescope data sets) is possible using a reduced proper motion diagram and a tangential velocity cut-off (depending on the proper motion accuracy) of 30km/s. Our near-infrared observations reveal eight new stars with significant absorption. We use the optical and near-infrared photometry to perform a detailed model atmosphere analysis. More than 80% of the stars in our sample are consistent with either pure hydrogen or pure helium atmospheres. However, the eight stars with significant infrared absorption and the majority of the previously known ultracool WD candidates are best explained with mixed hydrogen and helium atmosphere models. The age distribution of our sample is consistent with a Galactic disk age of 8Gyr. A few ultracool WDs may be as old as 12-13Gyr, but our models have problems matching the spectral energy distributions of these objects. There are only two halo WD candidates in our sample. However, trigonometric parallax observations are required for accurate mass and age determinations and to confirm their membership in the halo.2010ApJS..190...77Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/190/77CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/wd : Spectroscopically Identified White Dwarfs (McCook+, 2008)II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/AJ/127/3034 : Proper-motion catalog combining USNO-B and SDSS (Munn+, 2004)J/ApJ/607/426 : Catalog of white dwarfs in SDSS-DR1 (Kleinman+, 2004)J/AJ/131/582 : Cool white dwarfs in the SDSS (Kilic+, 2006)J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)J/A+A/448/579 : Sample of confirmed WDs in GSC-II survey (Carollo+, 2006)J/MNRAS/382/515 : SDSS ultracool and halo WD candidates (Vidrih+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/190/77https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/190/77http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/190/77https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/190/77https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/190/77http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/190/77GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/190/77/table1 (Optical and near-infrared photometry of cool white dwarfs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/190/77/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/190/77/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/190/77/table1?GETtext/xml+votable180.050000true0.8195417-1.18830560.005555555555555556Cone search capability for table J/ApJS/190/77/table2 (Spectroscopically identified subdwarf stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/190/77/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/190/77/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/190/77/table2?GETtext/xml+votable180.050000true139.950458343.93933330.0055555555555555566/552 4157 4826 4832 4861 5004 5012 5026 5069 5092 5106 5370 5467 5522 5571 5679 5707 5735 5741 5810 5832 5833 5843 5904 5911 5938 5953 6026 6027 6165 6404 6422 6452 6484 6524 6546 6576 7186 7248 7304 7363 7463 7473 7527 8192 8209 8340 8358 8381 8393 8712 8722 8742 9079 9162 9187 9242 9346 9364 9458 9516 9611 9732 9840 9846 9948 9954 10027 10183 10539 10573 10577 10608 10611 10659 10662 10699 10788 10838 10840 10863 10879 10902 10925 10930 10933 10963 11021 11062 11076 11135 11226 11247 11275 11287 11414 11422 11843 11940 12547 17304 17309 17405 17726 18388 18686 18791 18795 18860 18948 19022 19325 19689 19727 19732 19756 19987 20004 22716 23198 23201 23202 23212 25585 25937 26030 26039 26073 26103 26108 26172 26196 26229 26231 26251 26269 26271 26326 26358 26384 26415 26447 26468 26941 26965 27107 27404 27474 27670 27675 27740 27744 27746 27749 27815 27818 27843 27873 28170 30043 31334 31386 31482 32674 36729 36764 36805 36809 36863 49014 49016 49077 49098 49128 491498.562429046199531e-20 6.090060298487514e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/190/77?format=asciiOpticalInfrareddefaultJ/ApJS/190/77/table1Optical and near-infrared photometry of cool white dwarfsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS name (HHMMSS.ss+DDMMSS.s) (1)meta.id;meta.maincharprimaryumagu-band AB magnitude (2)magphot.mag;em.opt.Ufloatgmagg-band AB magnitude (2)magphot.mag;em.opt.Bfloatrmagr-band AB magnitude (2)magphot.mag;em.opt.Rfloatimagi-band AB magnitude (2)magphot.mag;em.opt.Ifloatzmagz-band AB magnitude (2)magphot.mag;em.opt.IfloatJmag? NIRI J-band magnitude (1.250um)magphot.mag;em.IR.Jfloatnullablee_Jmag? Jmag uncertaintymagstat.error;phot.mag;em.IR.JfloatnullableHmag? NIRI H-band magnitude (1.635um)magphot.mag;em.IR.Hfloatnullablee_Hmag? Hmag uncertaintymagstat.error;phot.mag;em.IR.HfloatnullableKmag? NIRI Ks-band magnitude (2.150um)magphot.mag;em.IR.Kfloatnullablee_Kmag? Kmag uncertaintymagstat.error;phot.mag;em.IR.KfloatnullableSpTSpectroscopic classificationsrc.spTypecharr_SpTOptical spectroscopic observations referencemeta.ref;pos.frameintnullableNep[4/6]? Number of epochs (for table2 only) (5)meta.numberintnullablefitSimbad column added by the CDSmeta.ref.urlcharSloanDisplay the SDSS data for this white dwarfmeta.ref.urlcharDR3Display the SDSS DR3 data (Abazajian et al. 2005, Cat. II/259)meta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idchar_RAPositions from SDSS name (right ascension part)degpos.eq.ra;meta.main_DEPositions from SDSS name (declination part)degpos.eq.dec;meta.mainJ/ApJS/190/77/table2Spectroscopically identified subdwarf starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS name (HHMMSS.ss+DDMMSS.s) (1)meta.id;meta.maincharumagu-band AB magnitude (2)magphot.mag;em.opt.Ufloatgmagg-band AB magnitude (2)magphot.mag;em.opt.Bfloatrmagr-band AB magnitude (2)magphot.mag;em.opt.Rfloatimagi-band AB magnitude (2)magphot.mag;em.opt.Ifloatzmagz-band AB magnitude (2)magphot.mag;em.opt.IfloatpmRAProper motion in RA from Munn et al. 2004, Cat. J/AJ/127/3034mas/yrpos.pm;pos.eq.raintnullablepmDEProper motion in Dec from Munn et al. 2004, Cat. J/AJ/127/3034mas/yrpos.pm;pos.eq.decintnullableNep[4/6]? Number of epochs (for table2 only) (5)meta.numberintnullableSloanDisplay the SDSS data for this white dwarfmeta.ref.urlcharDR3Display the SDSS DR3 data (Abazajian et al. 2005, Cat. II/259)meta.ref.urlcharUSNOB1Display the USNO-B1.0 data (Monet et al. 2003, Cat. I/284)meta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idchar_RAPositions from SDSS name (right ascension part)degpos.eq.ra;meta.main_DEPositions from SDSS name (declination part)degpos.eq.dec;meta.mainJ/ApJS/190/77/table3Best-fit model physical parameters assuming logg=8recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject name (JHHMM+DDMMA)meta.id;meta.maincharTeffEffective temperatureKphys.temperature.effectiveinte_TeffTeff uncertaintyKstat.error;phys.temperature.effectiveintDistDistancepcpos.distance;pos.heliocentricintAgeCooling ageGyrtime.agefloatCompComposition (logH/He)meta.codecharSpTSpectral typesrc.spTypecharpmRAProper motion in RAmas/yrpos.pm;pos.eq.raintpmDEproper motion in Decmas/yrpos.pm;pos.eq.decintPec[a-f, ] Peculiarities (1)meta.notecharSDSSSDSS name (HHMMSS.ss+DDMMSS.s) (added by CDS)meta.idchar