J/ApJ/730/67ivo://CDS.VizieR/J/ApJ/730/67doi:10.26093/cds/vizier.17300067CDSBrown J.M.Kilic M.Brown W.R.Kenyon S.J.2017-06-30T05:49:03Z2012-11-07T14:00:02ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsradial-velocityinfrared-photometrymultiple-starsWe describe spectroscopic observations of 21 low-mass (<=0.45M_{sun}_) white dwarfs (WDs) from the Palomar-Green survey obtained over four years. We use both radial velocities and infrared photometry to identify binary systems, and find that the fraction of single, low-mass WDs is <=30%. We discuss the potential formation channels for these single stars including binary mergers of lower-mass objects. However, binary mergers are not likely to explain the observed number of single low-mass WDs. Thus, additional formation channels, such as enhanced mass loss due to winds or interactions with substellar companions, are likely.2011ApJ...730...67Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/730/67CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/207 : Palomar-Green catalog UV-excess stellar objects (Green+ 1986)J/MNRAS/413/1121 : SDSS post-common envelope binaries. X (Rebassa-Mansergas+J/MNRAS/417/1210 : DA-white dwarfs from SDSS and UKIDSS (Girven+, 2011)J/ApJ/723/1072 : The ELM survey. I. Low-mass white dwarfs (Brown+, 2010)J/ApJ/712/585 : Apparent velocity measurements of DA WDs (Falcon+, 2010)J/AJ/135/1239 : Spectral distances to DA white dwarfs (Holberg+, 2008)J/AJ/132/1221 : VJHK and SDSS photometry of DA white dwarfs (Holberg+, 2006)J/ApJS/156/47 : White dwarfs from the Palomar Green Survey (Liebert+, 2005)J/AJ/124/1118 : RVs of high-velocity white dwarfs (Silvestri+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/730/67https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/730/67http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/730/67https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/730/67https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/730/67http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/730/67GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/730/67/wdwarfs (Physical and binary orbital parameters of the observed white dwarfs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/730/67/wdwarfs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/730/67/wdwarfs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/730/67/wdwarfs?GETtext/xml+votable180.050000true23.8087525.6622220.0055555555555555566/810 2075 4908 5420 5643 5827 7297 7697 8438 8671 8717 9484 10783 11017 11242 11336 11593 11835 19251 20100 20388 26172 26258 27429 27490 27859 27934 28358 28507 317141.398457827073138e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/730/67?format=asciiOpticalInfrareddefaultJ/ApJ/730/67/wdwarfsPhysical and binary orbital parameters of the observed white dwarfsl_M2[>=] Limit flag on M2meta.code.errorFtest? F-test significancestat.fit.goodnessdoublenullableMass? Mass (1)solMassphys.massfloatnullableTeff? Effective temperature (1)Kphys.temperature.effectiveintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharprimaryVSimbad column added by the CDSmeta.ref.urlcharf_Name[b] b: photometric binary (see table 3)meta.codecharVmag? V-band magnitude (1)magphot.mag;em.opt.VfloatnullableJmag? J-band magnitude (2)magphot.mag;em.IR.Jfloatnullablee_Jmag? Jmag uncertaintymagstat.error;phot.mag;em.IR.Jfloatnullablef_Jmag[p] p: our PAIRITEL photometrymeta.codecharr_Per[a-fMg ] References and notes (3)meta.ref;pos.framecharPer? Orbital perioddtime.periodfloatnullablee_Per? Per uncertaintydstat.errorfloatnullableKVelocity semiamplitude K (or standard deviation of the velocities for the 14 objects with no orbital fits)km/sphys.velocintu_KUncertainty flag on Kmeta.code.errorchare_K? K uncertaintykm/sstat.errorintnullableV0Systemic velocity {Gamma}km/sphys.velocinte_V0? {Gamma} uncertaintykm/sstat.error;pos.cartesian.yintnullableT0? Time of spectroscopic conjunction (T0-2450000)dtime.epochdoublenullablee_T0? T0 uncertaintydstat.errorfloatnullablef_Ftest[Hd/No] Flag on Ftest (4)meta.codecharMF? Mass function MFsolMassphys.massfloatnullableu_MFUncertainty flag on MFmeta.code.errorchare_MF? MF uncertaintysolMassstat.errorfloatnullableM2? Minimum companion mass M_2_solMassphys.mass;stat.minfloatnullableu_M2Uncertainty flag on M2meta.code.errorcharl_tau[<=] Limit flag on taumeta.code.errortau? Maximum merger time {tau}Gyrtime.epoch;stat.maxfloatnullableu_tauUncertainty flag on taumeta.code.errorcharNotesNote(s) (5)meta.notecharL05Link to the DA Wds from the PG survey catalogmeta.ref.urlcharVCVelocity curve (from table 4)meta.ref.urlchar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246) within 10"meta.ref.urlcharSimbadSimbad column added by the CDSmeta.refchar_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/ApJ/730/67/table4Radial velocity measurements (for 22 WDs)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject namemeta.id;meta.maincharHJDHeliocentric Julian date; (HJD-2450000.0)dtime.epochdoubleHRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRVUncertainty in HRVkm/sstat.errorfloatn_HRV[Mg ] MgI triplet lines (for PG 1458+172, see Note (3) above).meta.notechar