J/ApJ/723/1072ivo://CDS.VizieR/J/ApJ/723/1072doi:10.26093/cds/vizier.17231072CDSBrown W.R.Kilic M.Prieto C.A.Kenyon S.J.2017-06-22T14:28:29Z2012-08-14T08:15:15ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsradial-velocityvisible-astronomysloan-photometryspectroscopic-binary-starsstellar-massesWe analyze radial velocity observations of the 12 extremely low-mass (ELM), with <=0.25M_{sun}_, white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binaries with orbital periods shorter than 14hr; the one non-variable WD is possibly a pole-on system among our non-kinematically selected targets. Our sample is unique: it is complete in a well-defined range of apparent magnitude and color. The orbital mass functions imply that the unseen companions are most likely other WDs, although neutron star companions cannot be excluded. Six of the eleven systems with orbital solutions will merge within a Hubble time due to the loss of angular momentum through gravitational wave radiation. The quickest merger is J0923+3028, a g=15.7 ELM WD binary with a 1.08hr orbital period and a <=130Myr merger time. The chance of a supernova Ia event among our ELM WDs is only 1%-7%, however. Three binary systems (J0755+4906, J1233+1602, and J2119-0018) have extreme mass ratios and will most likely form stable mass-transfer AM CVn systems. Two of these objects, SDSS J1233+1602 and J2119-0018, are the lowest surface gravity WDs ever found; both show CaII absorption likely from accretion of circumbinary material. We predict that at least one of our WDs is an eclipsing detached double WD system, important for constraining helium core WD models.2010ApJ...723.1072Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/723/1072CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/306 : The SDSS Photometric Catalog, Release 8 (Adelman-McCarthy+, 2011)J/MNRAS/413/1121 : SDSS post-common envelope binaries. X (Rebassa-Mansergas+J/ApJ/671/1708 : Hypervelocity stars. III (Brown+, 2007)J/ApJ/660/311 : Hypervelocity stars. II. (Brown+, 2007)J/ApJ/647/303 : Spectroscopic survey of hypervelocity stars (Brown+, 2006)J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)J/AJ/132/1221 : VJHK and SDSS photometry of DA white dwarfs (Holberg+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/723/1072https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/723/1072http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/723/1072https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/723/1072https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/723/1072http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/723/1072GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/723/1072/elm_wd (White dwarf physical and binary orbital parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/723/1072/elm_wd?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/723/1072/elm_wd?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/723/1072/elm_wd?GETtext/xml+votable180.050000true118.968345849.10775280.0055555555555555566/4976 5948 6426 6636 7185 8346 8419 8991 9270 10606 19109 27951https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/723/1072?format=asciiOpticaldefaultJ/ApJ/723/1072/elm_wdWhite dwarf physical and binary orbital parametersSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameWhide dwarf name (JHHMM+DDMM)meta.id;meta.maincharprimaryr_Name[abc] Reference (G1)meta.ref;pos.framecharNvNumber of radial velocity measures for this white dwarfmeta.numberintnullableVCVelocity curvemeta.ref.urlchargmag0Corrected g-band magnitudemagphot.mag;em.opt.Bfloate_gmag0Corrected g-band magnitude uncertaintymagstat.error;phot.magfloat(u-g)0Corrected (u-g) color indexmagphot.color;em.opt.U;em.opt.Bfloate_(u-g)0Corrected (u-g) color index uncertaintymagstat.errorfloat(g-r)0Corrected (g-r) color indexmagphot.color;em.opt.B;em.opt.Rfloate_(g-r)0Corrected (g-r) color index uncertaintymagstat.errorfloatTeffEffective temperatureKphys.temperature.effectiveinte_TeffEffective temperature uncertaintyKstat.error;phys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloate_loggSurface gravity uncertaintylog(cm.s**-2)stat.errorfloatgMAGAbsolute g-band magnitudemagphot.magfloatDistHeliocentric distancekpcpos.distancefloatMassMasssolMassphys.massfloatPer? Orbital perioddtime.perioddoublenullablee_Per? Per uncertaintydstat.errordoublenullableKRadial velocity semi-amplitude (K)km/sspect.dopplerVelocinte_KK uncertaintykm/sstat.errorintVsysSystemic velocitykm/sphys.velocinte_VsysSystemic velocity uncertaintykm/sstat.errorintT0? Time of spectroscopic conjunction (-2450000)(1)dtime.epochdoublenullablee_T0? T0 uncertaintydstat.errordoublenullablef(M)? Binary mass function (2)solMassphys.massfloatnullablee_f(M)? Binary mass function uncertaintysolMassstat.errorfloatnullablel_M2[>= ] Limit flag on M2meta.code.errorM2? Minimum secondary mass (assuming i=90{deg})solMassphys.mass;stat.minfloatnullablel_tau[<= ] Limit flag on taumeta.code.errortau? Merger time (3)Gyrtime.epochfloatnullableHVSCross-matches with HVS catalogs within 3"meta.ref.urlintnullable_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/ApJ/723/1072/table3Radial velocity measurements (also named A.1 in the paper)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameWD name (JHHMM+DDMM)meta.id;meta.maincharHJDHeliocentric Julian Date (HJD-2450000)dtime.epochdoubleHRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRVUncertainty in HRVkm/sstat.errorfloat