J/ApJ/881/135ivo://CDS.VizieR/J/ApJ/881/135doi:10.26093/cds/vizier.18810135CDSLei Z.Zhao J.Nemeth P.Zhao G.2021-09-10T12:28:55Z2021-02-10T13:45:08ZCDS support team

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

cds-question@unistra.frsubdwarf-starseffective-temperaturestellar-spectral-typessurveysThree hundred and eighty eight hot subdwarf stars have been identified by using the Hertzsprung-Russell (HR) diagram built from the second data release of the Gaia mission. By analyzing their observed Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) spectra, we characterized 186 sdB, 73 He-sdOB, 65 sdOB, 45 sdO, 12 He-sdO, and 7 He-sdB stars. The atmospheric parameters of these stars (e.g., Teff, logg, log(nHe/nH)) are obtained by fitting the hydrogen (H) and helium (He) line profiles with synthetic spectra calculated from non-local thermodynamic equilibrium model atmospheres. Among these stars, we have 135 new identified hot subdwarfs which have not been cataloged before. Although 253 stars appear in the catalog by Geier+ (2017, J/A+A/600/A50), only 91 of them have atmospheric parameters. Together with the 294 hot subdwarf stars found by Lei+ (Paper I, 2018, J/ApJ/868/70), we identified 682 hot subdwarf stars in total by using the Gaia HR-diagram and LAMOST spectra. These results demonstrate the efficiency of our method to combine large surveys to search for hot subdwarf stars. We found a distinct gap in our He-sdOB stars based on their He abundance, which is also presented in extreme horizontal branch (EHB) stars of the globular cluster {omega} Cen. The number fraction of the sample size for the two subgroups is very different between the two counterparts. However, the distinct gap between the H-sdB stars and He-sdOB stars in {omega} Cen is not visible in our sample. More interestingly, the He-sdB population with the highest He abundance in our sample is completely missing in {omega} Cen. The discrepancy between our field hot subdwarf stars and the EHB stars in {omega} Cen indicate different origins for the two counterparts.2019ApJ...881..135Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/881/135CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVI/65 : Evolutionary models of evolved stars (Dorman+ 1993)I/345 : Gaia DR2 (Gaia Collaboration, 2018)V/153 : LAMOST DR4 catalogs (Luo+, 2018)V/164 : LAMOST DR5 catalogs (Luo+, 2019)J/ApJ/419/596 : Pop I UV radiation models (Dorman+, 1993)J/ApJ/562/368 : UV photometry in NGC 2808 (Brown+, 2001)J/A+A/400/939 : Stellar parameters of 115 HQS sdB stars (Edelmann+, 2003)J/A+A/430/223 : Parameters of cool companions of sdB stars (Lisker+, 2005)J/MNRAS/409/582 : Helium-rich subluminous B stars abundances (Naslim+, 2010)J/A+A/526/A136 : Hot HB stars in {omega} Cen (Moehler+, 2011)J/A+A/547/A109 : Parameters of HB stars in {omega} Cen (Moni Bidin+, 2012)J/MNRAS/427/2180 : GALEX survey subdwarf atmospheric parameters (Nemeth+, 2012)J/A+A/551/A31 : New spectral classif. for hot subdwarfs (Drilling+, 2013)J/A+A/565/A100 : NGC 288 hot HB stars abundances (Moehler+, 2014)J/MNRAS/446/4078 : New white dwarf stars in SDSS DR10 (Kepler+, 2015)J/A+A/576/A44 : Hot subdwarf binaries from MUCHFUSS (Kupfer+, 2015)J/MNRAS/455/3413 : New WD and subdwarf stars in SDSS DR12 (Kepler+, 2016)J/ApJ/818/202 : Hot subdwarf stars in LAMOST DR1 (Luo+, 2016)J/A+A/600/A50 : Catalog of hot subdwarf stars (Geier+, 2017)J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diag. (Gaia Collaboration, 2018)J/A+A/618/A15 : Parameters of EHB stars in {omega} Cen (Latour+, 2018)J/ApJ/868/70 : Hot subdwarf stars from Gaia DR2 and LAMOST DR5 (Lei+, 2018)J/A+A/621/A38 : Gaia catalog of hot subluminous stars (Geier+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/881/135https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/881/135http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/881/135https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/881/135https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/881/135http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/881/135GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/881/135/table1 (Information on the 388 hot subdwarf stars identified in this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/881/135/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/881/135/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/881/135/table1?GETtext/xml+votable180.050000true0.0656819417.648046940.0055555555555555566/64 78 148 168 220 226 255 399 448 485 689 709 723 728 730 767 829 1009 1154 1177 1185 1213 1348 1389 1457 1555 2094 2100 2131 2198 2228 2246 2370 2463 2492 2498 2507 2600 2641 2661 2702 2714 2719 2754 2899 4106 4113 4123 4174 4178 4242 4258 4273 4357 4374 4399 4409 4456 4497 4516 4541 4598 4604 4644 4648 4664 4674 4709 4739 4741 4753 4782 4838 4848 4858 4860 4898 4957 4976 4982 5057 5062 5184 5199 5206 5252 5406 5544 5567 5586 5639 5654 5690 5724 5760 5838 5866 5884 5908 5917 5918 5944 6002 6011 6145 6171 6198 6208 6267 6276 6283 6306 6348 6349 6410 6435 6446 6455 6507 6544 6560 6562 6579 6588 6613 6617 6701 6706 6710 6724 6741 6747 6772 6807 6850 6879 6889 6975 6982 7009 7056 7072 7259 7384 7717 8206 8281 8283 8308 8325 8391 8441 8538 8550 8570 8572 8675 8746 8806 8833 8956 8959 9026 9102 9123 9130 9186 9211 9254 9268 9299 9357 9366 9384 9419 9475 9505 9510 9593 9633 9819 9882 9911 9947 9969 9975 10072 10296 10315 10322 10333 10376 10382 10400 10409 10440 10471 10963 10985 11047 11113 11300 11335 11802 12302 12314 12365 12373 12565 12566 12591 12613 12655 12717 12720 12722 12734 13505 13582 14240 15017 15041 15124 15306 17789 17864 18003 18098 18153 18178 18232 18409 18851 18863 18908 18937 18954 19004 19037 19038 19040 19068 19071 19098 19099 19118 19157 19241 19244 19312 19329 19330 19375 19386 19397 19404 19410 19415 19427 19436 19544 19653 19708 19875 19957 20072 20118 20156 20224 20261 20321 20337 21370 21829 22285 22308 22316 22321 22398 22415 22428 22438 22456 22458 22459 22461 22481 22484 22494 22496 22734 22996 23531 23735 23747 23777 23813 23821 23823 23828 23839 23860 23879 23883 23896 23899 23909 23991 23997 24003 24017 24032 24092 24111 24133 24138 24160 24184 24194 24248 24397 24404 24438 24442 24501 24529 24532 24534 24570 25531 25566 25582 25882 25905 25996 26066 26164 26215 26223 26317 26396 26413 26436 26553 27026 27227 27345 27350 27379 27486 27817 27834 27839 27871 27909 27912 27913 27918 27999 28262 28266 28323 28331 28408 28465 28579 28586 28622 31315 31413 31424 31438 31528 31550 31640 31741 32385 32485 32486 32489 32496 32674 409481.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/881/135?format=asciidefaultJ/ApJ/881/135/table1Information on the 388 hot subdwarf stars identified in this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000LAMOST Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-7.2/60.5] LAMOST Declination (J2000)degpos.eq.dec;meta.mainG17[*] Listed (*) in hot subdwarf catalog of Geier+ (2017, J/A+A/600/A50)meta.codecharN12[d] Listed (d) in Nemeth+ (2012, J/MNRAS/427/2180)meta.codecharobsIDLAMOST DR5 observation identifiermeta.id;obs.param;obslongL16[dd ] Listed (dd) in Luo+ (2016, J/ApJ/818/202)meta.codecharGaiaGaia DR2 source identifiermeta.id;meta.mainTeff[22580/105770] Effective Temperature from XTgrid fitKphys.temperature.effectiveinte_Teff[20/29720] Uncertainty in TeffKstat.error;phys.temperature.effectiveintlogg[5/7.1] Surface gravity from XTgrid fitlog(cm.s**-2)phys.gravityfloate_logg[0.01/0.5] Uncertainty in logglog(cm.s**-2)stat.errorfloatlog(nHe/nH)[-3.43/3.65] log, nHe/nH from XTgrid fitphys.abundfloate_log(nHe/nH)[0.02/0.8]? Uncertainty in log(nHe/nH)stat.errorfloatnullablel_log(nHe/nH)Upper limit flag for log(nHe/nH)meta.code.errorcharSNRU[10/160] Signal-to-Noise ratio in the u bandpos.cartesian.x;arith.ratiointGmag[10.64/18.25] Gaia DR2 G magnitudemagphot.mag;em.optfloatSpTSpectral Classificationsrc.spTypecharSimbadSimbad column added by the CDSmeta.ref.urlchar