J/A+A/628/A102ivo://CDS.VizieR/J/A+A/628/A102doi:10.26093/cds/vizier.36280102CDSKoester D.Kepler S.O.2021-07-08T15:54:26Z2019-08-13T07:55:46ZCDS support team

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

cds-question@unistra.frcarbon-starswhite-dwarf-starseffective-temperaturestellar-masseschemical-abundancesAmong the spectroscopically identified white dwarfs, a fraction smaller than 2% have spectra dominated by carbon lines, mainly molecular C_2_, but also in a smaller group by CI and CII lines. These are together called DQ white dwarfs. We derive atmospheric parameters Teff, logg, and carbon abundances for a large sample of these stars and discuss implications for their spectral evolution. Sloan Digital Sky Survey spectra and ugriz photometry were used, together with Gaia Data Release 2 parallaxes and G band photometry. These were fitted to synthetic spectra and theoretical photometry derived from model atmospheres. We found that the DQs hotter than Teff ~10000K have masses ~0.4M_{sun}_ larger than the classical DQ, which have masses typical for the majority of white dwarfs (~0.6M_{sun}_). We found some evidence that the peculiar DQ below 10000K also have significantly larger masses and may thus be the descendants of the hot and warm DQs above 10000K. A significant fraction of the hotter objects with Teff>14500K have atmospheres dominated by carbon.2019A&A...628A.102Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/628/A102CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-tohttp://skyserver.sdss.org : SDSS Home Pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/628/A102https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/628/A102http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/628/A102https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/628/A102https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/628/A102http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/628/A102GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/628/A102/tablea1 (SDSS objects with carbon features)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/628/A102/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/628/A102/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/628/A102/tablea1?GETtext/xml+votable180.050000true0.0481717-8.83566190.0055555555555555566/554 714 726 896 993-994 2082 4125 4146 4152 4154 4180 4199-4200 4237 4254 4275 4359 4362 4477 4519 4582 4718-4719 4752 4758 4770 4798 4821 4848 4953 4983 4990 5047 5065 5077 5105 5111 5121 5132 5170 5177 5208 5232 5265 5349 5353 5359 5394 5401 5416 5446 5494 5569 5572 5578 5689 5745 5823 5829 5832 5880 5897 5943 6011 6076 6120 6136 6163 6256 6351 6395 6400 6423 6519 6553 6573 6582 6606 6612 7177 7192 7210 7219 7248 7252 7265 7287 7405 7457 7556 7741 7786 8236 8243 8348 8354 8406 8415 8453 8462 8484 8519 8529 8532 8534 8635 8690 8792 8800 8819 8830 8861 8868 8873 8892 8922 8961-8962 9031 9033 9107 9130 9249 9320 9331 9366 9370 9408 9481 9486 9601 9783 9808 9863 9865 9872 9878 10021 10104 10121-10122 10255 10264 10307 10328 10477 10480-10481 10568 10587 10618 10625 10632 10709 10765 10800 10815 10869 10873 10878 10896 10902 10923 10958 10970 10978 11022 11075-11076 11136 11180 11238 11262 11294 11340 11344 11359 11405 11425 11452 11515 11840 11881 11968 12373 12639 12737 16032 17229 17299 17344 17662 17754 17807 17811 18032 18107 18147 18245 18298 18339 18616 18627 18750 18765 18842 18999 19059 19092 19094 19165 19332-19333 19375 19403 19430 19691 19724 19776 19876 20149 20201 20322 20455 21884 21953 21973 22010 22352 22398 23187 23275 23429 23465 25530 25939 26010 26026 26058 26091 26171 26222 26358 26387 26428 26432 26486 26514-26515 26532 26583 26595 26612 26954 26960 27075 27214 27227 27249 27321 27336 27373 27522 27539 27593 27670 27688 27730 27782 27852 28009 28123 28147 28196 28225 28237 28259-28260 28297 28306 28316 28322 28344 28428 28621 31383 31442 31465 31530 31535 31622 31650 31663 31696 31730 32525 36729 45046 49077 490981.9867573869263685e-19 4.653515163505597e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/628/A102?format=asciidefaultJ/A+A/628/A102/tablea1SDSS objects with carbon featuresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSJSDSS name (HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharP-M-Fplate-epoch-fiber of spectrummeta.idcharprimaryPlxGaia parallax in milli-arcsecmarcsecpos.parallax.trigfloatgmagSDSS g magnitudemagphot.mag;em.opt.BfloatGmagGaia G magnitudemagphot.mag;em.optfloatS/NSignal-to-noise of SDSS spectrumstat.snrfloatSpTypeSpectral type (1)src.spTypecharParamindicates parameters in table A2meta.ref.urlcharSpInteractive spectrum from SDSSmeta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idchar_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/A+A/628/A102/tablea2Parameters for classical DQrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSJAbbreviated SDSS name (HHMM+DDMM)meta.id;meta.maincharP-M-FPlate-epoch-fiber of spectrummeta.idcharTeffEffective temperature (Kelvin)Kphys.temperature.effectiveinte_TeffError effective temperatureKstat.error;phys.temperature.effectiveintlogglog surface gravity in cgslog(cm.s**-2)phys.gravityfloate_loggError log surface gravitylog(cm.s**-2)stat.errorfloat[C/He]log(C/He) number abundance ratiometa.idfloate_[C/He]Error of abundance ratiostat.error;phys.abundfloatMassMass in solar unitssolMassphys.massfloate_MassError of masssolMassstat.error;phys.massfloat