J/ApJ/889/49ivo://CDS.VizieR/J/ApJ/889/49doi:10.26093/cds/vizier.18890049CDSBrown W.R.Kilic M.Kosakowski A.Andrews J.J.Heinke C.O.,Agueros M.A.Camilo F.Gianninas A.Hermes J.J.Kenyon S.J.2022-07-07T18:10:37Z2021-08-06T11:57:43ZCDS support team

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

cds-question@unistra.frmultiple-starswhite-dwarf-starsvisible-astronomyspectroscopyradial-velocitystellar-massesstellar-distanceproper-motionsWe present the final sample of 98 detached double white dwarf (WD) binaries found in the Extremely Low Mass (ELM) Survey, a spectroscopic survey targeting <0.3M_{sun}_ He-core WDs completed in the Sloan Digital Sky Survey footprint. Over the course of the survey we observed ancillary low-mass WD candidates like GD 278, which we show is a P=0.19d double WD binary, as well as candidates that turn out to be field blue straggler/subdwarf A-type stars with luminosities too high to be WDs given their Gaia parallaxes. Here, we define a clean sample of ELM WDs that is complete within our target selection and magnitude range 15<g_0_<20mag. The measurements are consistent with 100% of ELM WDs being 0.0089<P<1.5d double WD binaries, 35% of which belong to the Galactic halo. We infer that these are mostly He+CO WD binaries given the measurement constraints. The merger rate of the observed He+CO WD binaries exceeds the formation rate of stable mass-transfer AM CVn binaries by a factor of 25, and so the majority of He+CO WD binaries must experience unstable mass transfer and merge. The systems with the shortest periods, such as J0651+2844, are signature LISA verification binaries that can be studied with gravitational waves and light.2020ApJ...889...49Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/889/49CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/psr : ATNF Pulsar Catalogue (Manchester+, 2005)III/129 : Spectroscopically Identified White Dwarfs (McCook+, 1987)V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)II/350 : VLT Survey Telescope ATLAS (Shanks+, 2015)V/146 : LAMOST DR1 catalogs (Luo+, 2015)I/343 : Gaia-PS1-SDSS (GPS1) proper motion catalog (Tian+, 2017)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)I/351 : The extended Gaia-PS1-SDSS (GPS1+) proper motion cat. (Tian+, 2020)J/MNRAS/287/867 : Edinburgh-Cape Blue Object Survey. Zone 1. (Kilkenny+ 1997)J/ApJ/647/303 : Spectroscopic survey of hypervelocity stars (Brown+, 2006)J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)J/MNRAS/382/1377 : SDSS WD main-sequence binaries (Rebassa-Mansergas+, 2007)J/MNRAS/402/620 : SDSS WD main-sequence binaries (Rebassa-Mansergas+, 2010)J/ApJ/723/1072 : The ELM survey. I. Low-mass white dwarfs (Brown+, 2010)J/ApJ/730/128 : Spectroscopy of DA WD from the SDSS-DR4 (Tremblay+, 2011)J/A+A/536/A43 : SDSS WD main-sequence bin. XII. (Nebot Gomez-Moran+, 2011)J/ApJ/743/138 : Spectroscopic survey of bright WDs (Gianninas+, 2011)J/ApJ/751/55 : MMT hypervelocity star survey. II. (Brown+, 2012)J/ApJS/204/5 : SDSS DR7 white dwarf catalog (Kleinman+, 2013)J/MNRAS/429/2143 : Hidden population of AM CVns in the SDSS (Carter+, 2013)J/A+A/557/A19 : Mass & age of extreme low-mass white dwarfs (Althaus+, 2013)J/ApJ/794/35 : Binary WDs atmospheric parameters (Gianninas+, 2014)J/MNRAS/446/4078 : New white dwarf stars in SDSS DR10 (Kepler+, 2015)J/ApJ/812/167 : The ELM survey. VI. 11 new ELM WD bin. (Gianninas+, 2015)J/ApJ/818/155 : The ELM survey. VII. 15 new ELM WD cand. (Brown+, 2016)J/MNRAS/455/3413 : New WD and subdwarf stars in SDSS DR12 (Kepler+, 2016)J/A+A/595/A35 : Low-mass helium WDs evolutionary models (Istrate+, 2016)J/ApJ/839/23 : Subdwarf A stars vs ELM WDs radial velocities (Brown+, 2017)J/MNRAS/471/4218 : 4 low-mass white-dwarf candidates velocities (Kilic+, 2017)J/MNRAS/472/4173 : Bright white dwarfs for high-speed photometry (Raddi+, 2017)J/MNRAS/475/2480 : Extremely-low mass white dwarf star (Pelisoli+, 2018)J/A+A/617/A6 : Seven new pulsating sdA stars (Bell+, 2018)J/A+A/638/A131 : Radial velocities of 643 DA white dwarfs (Napiwotzki+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/889/49https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/889/49http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/889/49https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/889/49https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/889/49http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/889/49GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/889/49/table2 (Measured and derived parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/889/49/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/889/49/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/889/49/table2?GETtext/xml+votable180.050000true4.09212083-0.723116670.0055555555555555566/316 654 761 2299 2562 2676 2895 3127 3259 4053 4102 4134 4369 4390 4573 4613 4628 4673 4676 4774 4813 4855 4976 4988 5035 5042 5109 5120 5126 5169 5276 5293 5444 5446 5450 5561 5653 5682 5791 5948 6015 6209 6306 6345 6377 6426 6429-6430 6447 6539 6542 6556-6557 6559 6588 6630 6633 6636 7185 7378 7524 7555 7772 7782 8257 8265 8346 8369 8404 8419 8427 8537 8583 8665 8784 8858 8945 8991 9270 9354 9376 9382 9433 9447 9730 9808 9920 9934 9984 10243 10321 10525 10606 10973 11116 11233 11336 11393 11604 12368 12574 12596 12639 12650 12747 12756 12795 13319 13363 13409 13552 14554-14555 16033 16872 16973 17231 17310 17551 17842 17936 18026 18084 18096 18252 18395 18753 18770 18831 18900 18929 18954 19073 19109 19114 19275 19402 19410 19580 19591 19799-19800 19908 20081 20216 21587 21590 21817 21868 21900 21961 21998 22518 22739 22782 22801 23126 23183 23839 25228 25507 25528 25694 25718 25946 25964 25993 26086 26170 26191 26243 26278 26360 26390 26410 26420 26588 26622 26958-26959 27019 27045 27059 27084 27254 27395 27421 27437 27475 27522 27564 27573 27624 27637 27656 27658 27689 27698 27814 27835 27925 27949 27951 28054 28148 28162 28199 28256 28409 28562 31359 31380 31422 31435 31443 31447 31531 31537 31714 32377 32459 32655 36533 36763 36843 40774 44597 48753 49133https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/889/49?format=asciiOpticaldefaultJ/ApJ/889/49/table2Measured and derived parametersNameSDSS DR9 (V/139) or Pan-STARRS (II/349; for 6 cases) namesmeta.id;meta.mainchare_Teff[90/570] Uncertainty in TeffKstat.error;phys.temperature.effectiveintVPVelocity Plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBinDisplay the binary parameters (Table 3) for this starmeta.ref.urlcharNrvNumber of radial velocity measurements for this star (link to Table 1)meta.numberintnullableIDObject identifier (JHHMM+DDMM)meta.idcharprimaryRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.maingmag[12.7/20.6] Apparent g band magnitude; dereddened (1)magphot.mag;em.opt.Bfloate_gmag[0.003/0.1] Uncertainty in gmagmagstat.error;phot.magfloatTeff[6679/37250] Effective temperature (2)Kphys.temperature.effectiveintlog(g)[4.6/8.1] log surface gravity (2)log(cm.s**-2)phys.gravityfloate_log(g)[0.04/0.4] Uncertainty in log(g)log(cm.s**-2)stat.errorfloatWDWhite dwarf flag (1=True; 122 occurrences)meta.code.errorintELMELM white dwarf flag (1=True; 79 occurrences)meta.codeintCleanELM white dwarf in clean sample (1=True; 62 occurrences)meta.codeintDisk? Object that orbits in the disk (1=True; 81 occurrences)meta.codeintnullableMass[0.14/0.7] Mass (3)solMassphys.massfloate_Mass[0.01/0.05] Uncertainty in MasssolMassstat.error;phys.massfloatgMag[4.6/11.3] Absolute g band magnitude (3)magphys.magAbsfloate_gMag[0.03/1] Uncertainty in gMagmagstat.error;phot.magfloatDist[0.08/10.3] Heliocentric distance (3)kpcpos.distancefloate_Dist[0.006/4] Uncertainty in Distkpcstat.errorfloatplx[-0.8/13]? Parallax (4)maspos.parallax.trigfloatnullablee_plx[0.03/1.6]? Uncertainty in plxmasstat.error;pos.parallaxdoublenullablepmRA[-132/235] Proper motion along RA (4)mas/yrpos.pm;pos.eq.radoublee_pmRA[0.04/5] Uncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.radoublepmDE[-179/51] Proper motion along DE (4)mas/yrpos.pm;pos.eq.decdoublee_pmDE[0.04/5] Uncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatGaiaGaia DR2 source identifiermeta.id.crossPap7Display data from Paper VII (Brown+, 2016, J/ApJ/818/155) if anymeta.ref.urlintnullableSloanDisplay the online SDSS-DR14 data for the nearest objectmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/889/49/table3Binary parametersVPVelocity Plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject identifier (JHHMM+DDMM)meta.idcharNobs[5/78] Number of spectroscopic observationsmeta.numberintPer[0.0088/1.6] Binary orbital perioddtime.perioddoublee_Per[1e-5/0.11] Uncertainty in Perdstat.errordoubleK[26/618] Radial velocity semi-amplitudekm/sspect.dopplerVelocfloate_K[1/115] Uncertainty in Kkm/sstat.errorfloatgamma[-352/199] Systemic velocity corrected for gravitational redshiftkm/sphys.velocfloate_gamma[1.6/161] Uncertainty in gammakm/sstat.errorfloatM2[0.02/2.3] Minimum secondary masssolMassphys.mass;stat.minfloatlogtau[6/12.7] log maximum gravitational merger timescalelog(yr)time.scalefloatAlias?[0/1] Binary with a significant period alias (1=True)meta.codeintDelchi2[0/11372] The {chi}^2^ at Palias relative to the global {chi}^2^ minimummeta.notedoublePalias[0.0098/1.82] Period of the aliasdtime.perioddoubleStrain[0.17/160]? Characteristic strain times the S/N boost (1)stat.fit.paramfloatnullableE_Strain[0.05/138]? The 84.1% uncertainty in Strainstat.error;stat.maxfloatnullablee_Strain[0.04/45]? The 15.9% uncertainty in Strainstat.errorfloatnullableJ/ApJ/889/49/table1Radial velocity measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject identifier (JHHMM+DDMM)meta.idcharHJDHeliocentric Julian Date; JD-2450000dtime.epochdoubleHRV[-600/697] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[2/84] Uncertainty in HRVkm/sstat.errorfloat