J/ApJ/936/5ivo://CDS.VizieR/J/ApJ/936/5doi:10.26093/cds/vizier.19360005CDSWang K.Nemeth P.Luo Y.Chen X.Jiang Q.Cao X.2026-02-10T20:05:33Z2024-07-02T07:32:10ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsvisible-astronomyspectroscopyeffective-temperatureradial-velocitystellar-massesstellar-radiiWe present the first results from our ongoing project to study extremely low-mass (ELM) white dwarfs (WDs) (M<~0.3M{sun}) with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. Based on the LAMOST DR8 spectral database, we analyzed 136 ELM WD candidates selected from Gaia DR2 data and 12 known objects previously identified by the ELM Survey. The atmospheric parameters and radial velocities of these stars were obtained by fitting the LAMOST low-resolution spectra. After comparing the atmospheric parameters of the 12 known objects from this work to the results reported by the ELM Survey, we demonstrated the potential of LAMOST spectra in probing into the nature of ELM WDs. Based on the atmospheric parameters and Gaia EDR3 data, we identified 21 new high-probability ELM WDs with masses M<~0.3M{sun} and parallax estimates that agree to within a factor of 3. Two of them, J0338+4134 and J1129+4715, show significant radial velocity variability and are very likely to be binary systems containing at least one ELM WD.2022ApJ...936....5Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/936/5CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/350 : Gaia EDR3 (Gaia Collaboration, 2020)V/146 : LAMOST DR1 catalogs (Luo+, 2015)J/A+A/339/123 : PSR J1012+5307 evolutionary tracks (Driebe+ 1998)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/MNRAS/427/2180 : GALEX survey subdwarf atmospheric params (Nemeth+, 2012)J/A+A/557/A19 : Mass & age extreme low-mass white dwarfs (Althaus+, 2013)J/A+A/595/A35 : Low-mass He white dwarfs evolutionary (Istrate+, 2016)J/MNRAS/455/3413 : White dwarf & subdwarf stars in SDSS DR12 (Kepler+, 2016)J/MNRAS/469/2102 : White dwarf pop from the SDSS DR12 (Anguiano+, 2017)J/A+A/617/A6 : Seven new pulsating sdA stars (Bell+, 2018)J/MNRAS/488/2892 : Gaia DR2 extremely low-mass WD cands (Pelisoli+, 2019)J/ApJ/889/49 : ELM Survey. VIII. Final double WD binaries (Brown+, 2020)J/ApJ/894/53 : ELM Survey South. I. RVs for 6 ELM WDs (Kosakowski+, 2020)J/ApJS/256/28 : Hot subdwarf stars Gaia DR2 & LAMOST DR7 data (Luo+, 2021)J/other/RAA/21.292 : LAMOST Time-Domain survey, first results (Wang+, 2021)J/A+A/661/A113 : Hot subdwarf * Radial velocity variability (Geier+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/936/5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/936/5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/936/5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/936/5https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/936/5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/936/5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/936/5/table1 (Measured parameters for the 188 LAMOST low-resolution spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/936/5/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/936/5/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/936/5/table1?GETtext/xml+votable180.050000true0.2223638946.893558890.005555555555555556Cone search capability for table J/ApJ/936/5/table2 (Comparison of the atmospheric parameters from this work to the results published in ELM survey paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/936/5/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/936/5/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/936/5/table2?GETtext/xml+votable180.050000true47.07578551.669866940.005555555555555556Cone search capability for table J/ApJ/936/5/table3 (Physical parameters of the 21 high-probability ELM WDs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/936/5/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/936/5/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/936/5/table3?GETtext/xml+votable180.050000true14.6545588944.908566940.0055555555555555566/305 496 614 932 1110 1188 1337 1362 1442-1443 1532 1555 1684 1702 1773 1833 1970 2383 2509 2573 2591 2681 2719 2750 2806 2808 2877 3088 3094 3108 3127 3414 4476 4555 4598 4641 4722 4752 4772 4774 4937 4955 4976 5111 5235 5252 5332 5420 5583 5643 5791 6173 6198 6473 6544 6556 6633 6680 6703 6807 6840 6932 8784 8838 8858 9126 9376 9891 9966 10418 10658 10825 10945 12574 12598 13433 13671 13772 13818 13848 13960 14467 14553 17859 18132 18890 19243 19319 19397 19907-19908 19966 20066 20320 22202 22279 22314 22428 22438 22463 22472 22739 22777 22867 22917 22996 23004 23101 23108 23182 23325 23438 23563 23657 23668 23811 23823 24067 24101 24133 24136 24163 24184 24199 24253 24282 24341 24363 26396 26420 26465 26572 26953 27226 27240 27433 27475 27680 27949 28148 28212 28651 31736 31812 31816 31963 32135 40774https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/936/5?format=asciiOpticaldefaultJ/ApJ/936/5/table1Measured parameters for the 188 LAMOST low-resolution spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjectObject short namemeta.id;meta.maincharprimaryRAJ2000[0/354] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-3/67] Declination (J2000)degpos.eq.dec;meta.mainTeff[7570/114540] Surface effective temperatureKphys.temperature.effectiveinte_Teff[40/31380] Uncertainty in TeffKstat.error;phys.temperature.effectiveintSimbadNameSimbad column added by the CDSmeta.idcharnullablel_loggLimit flag on loggmeta.code.errorcharlogg[2.058/8.796] log, surface gravitylog(cm.s**-2)phys.gravityfloate_logg[0.01/1.716]? Uncertainty in logglog(cm.s**-2)stat.errorfloatnullablel_yLimit flag on ymeta.code.error;pos.cartesian.ychary[-5.689/1.69] log, nHe/nHphys.abund.Yfloate_y[0.001/1.767]? Uncertainty in ystat.errorfloatnullableRVel[-448.5/351.6] Radial velocitykm/sspect.dopplerVelocfloate_RVel[1.9/150.0] Uncertainty in RVelkm/sstat.error;spect.dopplerVelocfloatSNRg[10.2/97.8] Signal-to-noise in g-bandmeta.notefloatNotesNotes (1)meta.notecharJ/ApJ/936/5/table2Comparison of the atmospheric parameters from this work to the results published in ELM survey paperObjectObject short namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFlaga=MMT spectra provided by Dr. Warren R. Brownmeta.code.errorcharRAJ2000[12/240] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-13/52] Declination (J2000)degpos.eq.dec;meta.mainTeff-XTgrid[7570/21160] Surface effective temperature, XTgridKphys.temperature.effectiveinte_Teff-XTgrid[50/680] Uncertainty in Teff-XTgridKstat.errorintl_logg-XTgridLimit flag on logg-XTgridmeta.code.errorcharlogg-XTgrid[4.905/7.474] log, surface gravity, XTgridlog(cm.s**-2)phys.gravityfloate_logg-XTgrid[0.01/0.233]? Uncertainty in logg-XTgridlog(cm.s**-2)stat.errorfloatnullableXTgrid-modelModel atmosphere used in XTgrid (1)meta.id;stat.fitcharTeff-B20[8096/21660] Surface effective temperature, Brown+, 2020, J/ApJ/889/49Kphys.temperature.effectiveinte_Teff-B20[100/380] Uncertainty in Teff-B20Kstat.errorintlogg-B20[5.045/7.76] log, surface gravity, Brown+, 2020, J/ApJ/889/49log(cm.s**-2)phys.gravityfloate_logg-B20[0.041/0.112] Uncertainty in logg-B20log(cm.s**-2)stat.errorfloatJ/ApJ/936/5/table3Physical parameters of the 21 high-probability ELM WDsObjectObject short namemeta.id;meta.maincharlogg[4.667/7.21] log, surface gravitylog(cm.s**-2)phys.gravityfloate_logg[0.037/0.367] Uncertainty in logglog(cm.s**-2)stat.errorfloatMass[0.159/0.334] Mass, solar unitssolMassmeta.unit;phys.massfloate_Mass[0.011/0.07] Uncertainty in MasssolMassstat.error;phys.massfloatRad[0.024/0.36] Radius, solar unitssolRadmeta.unit;phys.size.radiusfloate_Rad[0.003/0.078] Uncertainty in RadiussolRadstat.errorfloatplx-gaia[0.1469/6.2726] Parallax, Gaia EDR3maspos.parallax.trigfloate_plx-gaia[0.0283/0.1644] Uncertainty in plx-gaiamasstat.errorfloatplx-spec[0.3702/2.7432] Spectroscopic parallax, Equation 3maspos.parallax.spectfloate_plx-spec[0.0408/1.4252] Uncertainty in plx-specmasstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[14/354] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-3/51] Declination (J2000)degpos.eq.dec;meta.mainTeff[9390/26680] Surface effective temperatureKphys.temperature.effectiveinte_Teff[40/3110] Uncertainty in TeffKstat.error;phys.temperature.effectiveint