J/AJ/150/42ivo://CDS.VizieR/J/AJ/150/42doi:10.26093/cds/vizier.51500042CDSZhong J.Lepine S.Hou J.Shen S.Yuan H.Huo Z.Zhang H.Xiang M.,Zhang H.Liu X.2017-09-26T07:12:45Z2015-10-07T12:52:55ZCDS support team

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

cds-question@unistra.frdwarf-starsm-starsstellar-spectral-typesproper-motionsinfrared-photometryWe develop a template-fit method to automatically identify and classify late-type K and M dwarfs in spectra from the Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST). A search of the commissioning data, acquired in 2009-2010, yields the identification of 2612 late-K and M dwarfs. The template fit method also provides spectral classification to half a subtype, classifies the stars along the dwarf-subdwarf (dM/sdM/esdM/usdM) metallicity sequence, and provides improved metallicity/gravity information on a finer scale. The automated search and classification is performed using a set of cool star templates assembled from the Sloan Digital Sky Survey spectroscopic database. We show that the stars can be efficiently classified despite shortcomings in the LAMOST commissioning data which include bright sky lines in the red. In particular we find that the absolute and relative strengths of the critical TiO and CaH molecular bands around 7000{AA} are cleanly measured, which provides accurate spectral typing from late-K to mid-M, and makes it possible to estimate metallicity classes in a way that is more efficient and reliable than with the use of spectral indices or spectral-index based parameters such as {zeta}_TiO/CaH_. Most of the cool dwarfs observed by LAMOST are found to be metal-rich dwarfs (dM). However, we identify 52 metal-poor M subdwarfs (sdM), 5 very metal-poor extreme subdwarfs (esdM) and 1 probable ultra metal-poor subdwarf (usdM). We use a calibration of spectral type to absolute magnitude and estimate spectroscopic distances for all the stars; we also recover proper motions from the SUPERBLINK and PPMXL catalogs. Our analysis of the estimated transverse motions suggests a mean velocity and standard deviation for the UVW components of velocity to be: <U>=-9.8km/s, {sigma}_U_=35.6km/s; <V> =-22.8km/s, {sigma}_V_=30.6km/s; <W> =-7.9km/s, {sigma}_W_=28.4km/s. The resulting values are in general agreement with previous reported results, which yields confidence in our spectral classification and spectroscopic distance estimates, and illustrates the potential for using LAMOST spectra of K and M dwarfs for investigating the chemo-kinematics of the local Galactic disk and halo.2015AJ....150...42Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/150/42CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/139 : The SDSS Photometric Catalog, DR 9 (Adelman-McCarthy+, 2012)I/317 : The PPMXL Catalog (Roeser+ 2010)II/294 : The SDSS Photometric Catalog, DR7 (Adelman-McCarthy+, 2009)I/298 : LSPM-North Catalog (Lepine+ 2005)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/AJ/145/102 : Spectroscopy of bright M dwarfs in northern sky (Lepine+, 2013)J/AJ/145/52 : Abundances of late K and M dwarfs in binary stars (Mann+, 2013)J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)J/AJ/130/1680 : LSPM-North proper-motion catalog nearby stars (Lepine+, 2005)J/AJ/125/1598 : New high proper motion stars in northern sky (Lepine+, 2003)J/AJ/113/806 : M-Subdwarfs (Gizis 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/150/42https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/150/42http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/150/42https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/150/42https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/150/42http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/150/42GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/150/42/table4 (M dwarf catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/150/42/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/150/42/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/150/42/table4?GETtext/xml+votable180.050000true91.2519419421.450030.0055555555555555564/62 5/242 243 654 655 663 664 666 669 676 677 706 707 712 1833 1835 1836 1838 5455 5466 5477 5488 6081 6083 6084 6086 6/927 949 951 957 959 984 986 1008 1010 1016 2613 2614 2615 2651 2673 2675 2681 2684 2685 2713 2716 2752 2753 2754 2819 2822 2823 2852 2853 2854 2856 7331 7339 7348 7350 7356 7358 7681 7684 7685 7696 7697 21815 21858 21859 21868 21869 21870 21957 21958 21959 21960 21961 21964 23982 23983 23994 24321 24323 24329 24331 24342 24348 24350 24353 24356 24357 24368 243698.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/150/42?format=asciiOpticalInfrareddefaultJ/AJ/150/42/table4M dwarf catalogSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension (J2000), at Epoch J2000degpos.eq.ra;meta.maine_RAJ2000[15/133]? Mean error in RAdegmasstat.error;pos.eq.raintnullableDEJ2000Declination (J2000), at Epoch J2000degpos.eq.dec;meta.maine_DEJ2000[15/133]? Mean error in DEdegmasstat.error;pos.eq.decintnullablepmRA[-147.2/374.5]? Proper motion in RA*cos(DEdeg)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA[1.2/21.9]? Mean error in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE[-212.7/114.8]? Proper motion in DEmas/yrpos.pm;pos.eq.decfloatnullablee_pmDE[1.2/21.9]? Mean error in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatnullabler_pmDE[LSPT] Source of the proper motion (1)meta.ref;pos.pm;pos.eq.deccharPPMDetails from PPMXLmeta.ref.urlcharJmag[10.8/16.6]? 2MASS J band magnitude (2)magphot.mag;em.IR.JfloatnullableHmag[9.66/15.92]? 2MASS H band magnitude (2)magphot.mag;em.IR.HfloatnullableKsmag[9.24/15.44]? 2MASS Ks band magnitude (2)magphot.mag;em.IR.KfloatnullableSpTSpectral type (3)src.spTypecharDist[29/1458]? Spectroscopic distance (4)pcpos.distance;pos.heliocentricintnullableSDSSNumber of sources in the SDSS-DR9 catalog (Cat. V/139) within 1.5''meta.ref.urlintnullableSloanDisplay the SDSS data for this starmeta.ref.urlchar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar