J/ApJ/934/36ivo://CDS.VizieR/J/ApJ/934/36doi:10.26093/cds/vizier.19340036CDSBergeron P.Kilic M.Blouin S.Bedard A.Leggett S.K.Brown W.R.2024-11-06T20:26:29Z2024-07-30T12:57:58ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsinfrared-photometryvisible-astronomybroad-band-photometryspectroscopyA recent analysis of the 100pc white dwarf sample in the SDSS footprint demonstrated for the first time the existence of a well-defined ultracool --or IR-faint-- white dwarf sequence in the Hertzsprung-Russell diagram. Here we take advantage of this discovery to enlarge the IR-faint white dwarf sample threefold. We expand our selection to the entire Pan-STARRS survey footprint as well as the Montreal White Dwarf Database 100pc sample and identify 37 candidates with strong flux deficits in the optical. We present follow-up Gemini optical spectroscopy of 30 of these systems and confirm all of them as IR-faint white dwarfs. We identify an additional set of 33 objects as candidates based on their colors and magnitudes. We present a detailed model atmosphere analysis of all 70 newly identified IR-faint white dwarfs together with 35 previously known objects reported in the literature. We discuss the physics of model atmospheres and show that the key physical ingredient missing in our previous generation of model atmospheres was the high-density correction to the He^-^ free-free absorption coefficient. With new model atmospheres calculated for the purpose of this analysis, we now obtain significantly higher effective temperatures and larger stellar masses for these IR-faint white dwarfs than the T_eff_ and M values reported in previous analyses, thus solving a two-decade-old problem. In particular, we identify in our sample a group of ultramassive white dwarfs in the Debye cooling phase with stellar parameters never measured before.2022ApJ...934...36Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/934/36CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/wd : Spectroscopically identified white dwarfs (McCook+, 2014)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)II/367 : The VISTA Hemisphere Survey (VHS) catalog DR5 (McMahon+, 2020)V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/other/Sci/292.698 : Candidate halo dark matter (Oppenheimer+, 2001)J/AJ/131/582 : Cool white dwarfs in the SDSS (Kilic+, 2006)J/ApJ/663/1291 : DZ stars in SDSS DR4 (Dufour+, 2007)J/A+A/465/249 : Age and colors of massive white dwarf stars (Althaus+, 2007)J/ApJS/190/77 : Detailed analysis of cool WDs in the SDSS (Kilic+, 2010)J/A+A/557/A19 : Mass & age of extreme low-mass white dwarfs (Althaus+, 2013)J/other/SCPMA/57.176 : Carbon stars & DZ white dwarfs in SDSS sp. (Si+ 2014)J/MNRAS/449/3966 : Ultracool white dwarfs (Gianninas+, 2015)J/A+A/595/A35 : Low-mass helium WDs evolutionary models (Istrate+, 2016)J/MNRAS/467/4970 : Cool DZ white dwarfs. I. (Hollands+, 2017)J/A+A/616/A10 : Open clusters GaiaDR2 HR diagrams (Gaia Collaboration, 2018)J/ApJS/239/26 : NOFS measurements for distant WDs (Leggett+, 2018)J/ApJ/872/199 : Cand. spectrophotometric standard DA WDs (Calamida+, 2019)J/ApJ/878/63 : Cool WD atm. models. IV. Spectral evolution (Blouin+, 2019)J/ApJ/901/93 : Model atm. analysis of hot WDs from SDSS (Bedard+, 2020)J/ApJ/898/84 : Sp. follow-up of 100pc WDs in SDSS & Gaia (Kilic+, 2020)J/MNRAS/497/130 : Gaia white dwarfs within 40pc. I (Tremblay+, 2020)J/MNRAS/499/1890 : Gaia white dwarfs within 40pc. II. (McCleery+, 2020)http://www.montrealwhitedwarfdatabase.org/ : Montreal WD database homepagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/934/36https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/934/36http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/934/36https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/934/36https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/934/36http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/934/36GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/934/36/table4 (*Best-fit parameters for IR-faint white dwarfs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/36/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/36/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/36/table4?GETtext/xml+votable180.050000true6.76220945.90927780.005555555555555556Cone search capability for table J/ApJ/934/36/table2 (Newly identified IR-faint white dwarfs with strong flux deficits in the optical bands)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/36/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/36/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/36/table2?GETtext/xml+votable180.050000true9.784896130.59437750.005555555555555556Cone search capability for table J/ApJ/934/36/table3 (Additional IR-faint white dwarf candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/36/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/36/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/36/table3?GETtext/xml+votable180.050000true6.76220945.90927780.0055555555555555566/376 474 696 869 954 1144 3170 4138 4832 5092 5411 5707 5833 6412 7186 7383 8641 8697 8739 9107 9242 9462 9908 10122 10183 10608 10699 10788 10863 11593 11656 12096 12785 13317 13663 13712 13918 14299 14671 14735 15734 16165 16697 16966 18388 18860 18971 19089 19521 19623 19868 20029 20311 20682 21155 22748 23106 23159 23212 23612 25232 25473 25486 25614 26025 26226 26423 26513 27157 27290 27674 27749 27817 28152 28184 28277 29910 29927 30474 30895 31150 31617 31652 31803 31862 31905 32238 33239 33999 35983 36014 36113 36190 36837 40164 40280 40600 40628 40949 43901 44138 44771 48385 48649https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/934/36?format=asciiOpticalInfrareddefaultJ/ApJ/934/36/table4*Best-fit parameters for IR-faint white dwarfsSimbadNameSimbad column added by the CDSmeta.idcharnullableONameMain names from the Montreal White Dwarf Database (link to https://www.montrealwhitedwarfdatabase.org)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameWhite dwarf identifiermeta.idcharprimaryTeff[3021/5561] Effective temperatureKphys.temperature.effectiveinte_Teff[17/3639]? Uncertainty in TeffKstat.error;phys.temperature.effectiveintnullableMass[0.2/1.3] MasssolMassphys.massfloatE_Mass[0/0.08] Upper uncertainty in MasssolMassstat.error;stat.max;phys.massfloate_Mass[0/0.1] Lower uncertainty in MasssolMassstat.error;stat.min;phys.massfloatlogH/He[-4.8/0.2] log H/He number abundancephys.abundfloatlogL[-5.1/-3.7] log luminositylog(solLum)phys.luminosityfloatCAge[3.6/23.96] Cooling ageGyrtime.agefloat_RAPositions from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD (declination part)degpos.eq.dec;meta.mainNewNewly identified IR-faint WD with S=strong flux deficits in opt. bands (Table 2) or M=milder deficits (Table 3)meta.ref.urlcharJ/ApJ/934/36/table2Newly identified IR-faint white dwarfs with strong flux deficits in the optical bandsNameWhite dwarf identifier (JHHMM+DDMM)meta.idcharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaGaia EDR3 identifiermeta.id;meta.mainplx[8.49/30.64] Gaia EDR3 parallaxmaspos.parallax.trigfloatpm[22.3/487.7] Gaia EDR3 proper motionmas/yrpos.pmfloatONamePan-STARRS or DES identifiermeta.idchargmag[18.2/21.1] Apparent g band AB magnitude (1)magphot.mag;em.opt.Bfloatrmag[17.77/20.64] Apparent r band AB magnitude (1)magphot.mag;em.opt.Rfloatimag[17.88/21.1]? Apparent i band AB magnitude (1)magphot.mag;em.opt.Ifloatnullablezmag[18.2/21.62]? Apparent z band AB magnitude (1)magphot.mag;em.opt.Ifloatnullableymag[18.4/21.3]? Apparent y band AB magnitude (1)magphot.mag;em.IR.JfloatnullableSpTWhite dwarf spectral type ("DC" or 1 occurrence of "DZ")src.spTypecharInstSpectral source (2)meta.id;instrcharFileNameName of the spectrum file in subdirectory "sp"; column added by CDSmeta.id;meta.filecharDESDisplay data from DES DR2 (II/371) within 5" if anymeta.ref.urlnullablePS1Display data from Pan-STARRS 1 (II/349) within 6" if anymeta.ref.urlintnullablespInteractive spectrum plotmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/934/36/table3Additional IR-faint white dwarf candidatesNameWhite dwarf identifier (JHHMM+DDMM)meta.idcharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaGaia EDR3 identifiermeta.id;meta.mainplx[9.6/28.3] Gaia EDR3 parallaxmaspos.parallax.trigfloatgmag[18.2/20.62] Apparent g band AB magnitude (1)magphot.mag;em.opt.Bfloatrmag[17.7/20.1] Apparent r band AB magnitude (1)magphot.mag;em.opt.RfloatSpTSpectral typesrc.spTypecharimag[17.5/20.02] Apparent i band AB magnitude (1)magphot.mag;em.opt.Ifloatzmag[17.59/20.21] Apparent z band AB magnitude (1)magphot.mag;em.opt.Ifloatymag[17.7/20.64]? Apparent y band AB magnitude (1)magphot.mag;em.IR.JfloatnullableDESDisplay data from DES DR2 (II/371) within 5" if anymeta.ref.urlnullablePS1Display data from Pan-STARRS 1 (II/349) within 6" if anymeta.ref.urlintnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main