J/ApJ/838/73ivo://CDS.VizieR/J/ApJ/838/73doi:10.26093/cds/vizier.18380073CDSMartin E.C.Mace G.N.McLean I.S.Logsdon S.E.Rice E.L.,Kirkpatrick J.D.Burgasser A.J.McGovern M.R.Prato L.2018-02-05T07:32:46Z2017-12-06T14:10:27ZCDS support team

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

cds-question@unistra.frinfrared-astronomyspectroscopyline-intensitiesstellar-spectral-typesstellar-agest-dwarfssurveysbrown-dwarfsWe combine 131 new medium-resolution (R~2000) J-band spectra of M, L, and T dwarfs from the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) with 97 previously published BDSS spectra to study surface-gravity-sensitive indices for 228 low-mass stars and brown dwarfs spanning spectral types M5-T9. Specifically, we use an established set of spectral indices to determine surface gravity classifications for all of the M6-L7 objects in our sample by measuring the equivalent widths (EW) of the K I lines at 1.1692, 1.1778, and 1.2529{mu}m, and the 1.2{mu}m FeH_J_ absorption index. Our results are consistent with previous surface gravity measurements, showing a distinct double peak-at ~L5 and T5-in K I EW as a function of spectral type. We analyze the K I EWs of 73 objects of known ages and find a linear trend between log(Age) and EW. From this relationship, we assign age ranges to the very low gravity, intermediate gravity, and field gravity designations for spectral types M6-L0. Interestingly, the ages probed by these designations remain broad, change with spectral type, and depend on the gravity-sensitive index used. Gravity designations are useful indicators of the possibility of youth, but current data sets cannot be used to provide a precise age estimate.2017ApJ...838...73Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/838/73CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)I/337 : Gaia DR1 (Gaia Collaboration, 2016)J/ApJ/476/311 : 2MASS M-dwarf discoveries (Kirkpatrick+ 1997)J/AJ/120/479 : Low-mass stars in the Upper Sco association (Ardila+, 2000)J/ApJ/564/421 : Spectra of T dwarfs. I. (Burgasser+, 2002)J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)J/AJ/124/1190 : Northern high proper motion stars in DSS (Lepine+, 2002)J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)J/AJ/125/3302 : HST binary very low mass stars and brown dwarfs (Gizis+, 2003)J/AJ/125/1598 : New high PM stars in the northern sky (Lepine+, 2003)J/AJ/127/3553 : JHK photom. and spectroscopy for L and T dwarfs (Knapp+, 2004)J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004)J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)J/AJ/130/1733 : Optical spectroscopy of {rho} Oph stars (Wilking+, 2005)J/ApJ/637/1067 : Near-IR spectral classification of T dwarfs (Burgasser+, 2006)J/AJ/131/2722 : New L and T dwarfs from the SDSS (Chiu+, 2006)J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)J/AJ/132/891 : Binaries among nearby L dwarfs (Reid+, 2006)J/AJ/131/3016 : Low-mass objects in Upper Scorpius (Slesnick+, 2006)J/AJ/134/1162 : 11 new T dwarfs in 2MASS (Looper+, 2007)J/ApJS/172/663 : Infrared observations of the Pleiades (Stauffer+, 2007)J/ApJ/689/1295 : Lithium test implications for BDs (Kirkpatrick+, 2008)J/ApJ/688/362 : Disks around BDs in {sigma} Ori cluster (Luhman+, 2008)J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)J/AJ/137/1 : PMs and astrometry of late-type dwarfs (Faherty+, 2009)J/ApJ/704/975 : Rotational velocities for M dwarfs (Jenkins+, 2009)J/ApJ/705/1416 : Volume-limited sample of M7-M9.5 dwarfs <20pc (Reiners+, 2009)J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)J/AJ/139/1808 : Colors and kinematics of SDSS L dwarfs (Schmidt+, 2010)J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)J/MNRAS/422/1495 : UKIDSS Gal. Clusters Survey Pleiades members (Lodieu+ 2012)J/MNRAS/426/3403 : UKIDSS-GCS {alpha} Per members (Lodieu+, 2012)J/ApJ/758/31 : IR photometry for members of Upper Sco (Luhman+, 2012)J/ApJ/744/134 : SONYC new brown dwarfs in {rho} Oph (Muzic+, 2012)J/ApJ/746/154 : Improved kinematic plxes for Sco-Cen members (Pecaut+, 2012)J/ApJS/205/6 : T dwarf population revealed by WISE (Mace+, 2013)J/ApJ/762/88 : Young stellar kinematic group candidate members (Malo+, 2013)J/PASP/125/809 : New nearby M, L, and T dwarfs (Thompson+, 2013)J/ApJ/783/121 : BANYAN II. Nearby young assoc. cand. members (Gagne+, 2014)J/ApJ/783/122 : AllWISE motion survey (Kirkpatrick+, 2014)J/AJ/147/34 : SpeX library of L-type dwarfs (Schneider+, 2014)J/ApJ/814/118 : L/T transition dwarfs search with PS1 & WISE II. (Best+, 2015)J/ApJ/798/73 : BANYAN All-Sky Survey (BASS) catalog. V. YMGs (Gagne+, 2015)J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/838/73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/838/73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/838/73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/838/73https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/838/73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/838/73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/838/73/table3 (BDSS objects with known ages)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/838/73/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/838/73/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/838/73/table3?GETtext/xml+votable180.050000true341.13197520.728694440.005555555555555556Cone search capability for table J/ApJ/838/73/bdss (Observations, equivalent widths and spectral index values for the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) J-band spectra (tables 1 and 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/838/73/bdss?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/838/73/bdss?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/838/73/bdss?GETtext/xml+votable180.050000true94.9691667-29.06644440.0055555555555555566/223 439 463 466 472 474 485 496 749 762 771 968 1028 1031 1073 1074 1075 1159 1168 1499 1692 1703 1772 1774 1825 2044 2101 3093 3101 3136 3144 3965 4074 4253 4316 4685 4709 4780 4790 4948 5147 5186 5200 5413 5540 5569 5718 5854 5939 6629 6844 7291 7592 8192 8361 8402 8422 8440 8478 8558 8625 8727 9009 9063 9173 9479 9569 10069 10142 10203 10292 10445 11205 11510 12253 12262 12600 13425 13455 13559 13669 13736 13842 13885 14850 15530 15846 15994 16867 16983 17075 17166 18155 18281 18300 18563 18683 19369 19680 19813 19857 19906 19963 20141 20326 20374 20436 20468 20591 20594 21296 21637 21861 22521 22555 22681 22759 22851 22854 22950 22996 23355 23548 23549 23882 24580 24694 24707 24716 25015 25443 25515 25853 25945 26005 26186 26210 26861 27110 27201 27362 27462 27653 28006 28055 28148 28277 28427 28473 30505 30833 30956 31319 31871 32284 32337 32426 32574 32596 32609 32650 33767 34428 34535 34645 35202 35499 35509 36418 36602 40297 40332 40623 40656 40738 40941 42981 42982 42986 42988 42989 43957 43966 44259 44286 44295 44309 44311 44317 44318 44363 44365 44372 44376 44388 44807 44929 44954 47866 47997 48593 48637 48957 48990 49139 49140https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/838/73?format=asciiInfrareddefaultJ/ApJ/838/73/refsReferencesRef[1/1111] Reference codemeta.noteintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBibCodeBibcode of the referencemeta.bib.bibcodecharAuthFirst author's namemeta.bib.authorcharCommComment (Catalog's reference)meta.ref;pos.frame;meta.tablecharJ/ApJ/838/73/table3BDSS objects with known agesNotesNotesmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainSpTMK spectral typesrc.spTypecharl_Age[<*] Limit flag on Age (*: range 80-300)meta.code.error;time.agecharAge[0.3/750]? AgeMyrtime.agefloatnullablee_Age? Negative uncertainty on AgeMyrstat.error;time.agefloatnullableE_Age? Positive uncertainty on AgeMyrstat.error;stat.maxfloatnullableTypeGravity type (G1)src.classcharMm[54/100]? Membership probability%statfloatnullablef_MmAmb: ambiguousmeta.codecharr_MmMembership reference(s) (see refs.dat file)meta.ref;pos.framecharJ/ApJ/838/73/bdssObservations, equivalent widths and spectral index values for the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) J-band spectra (tables 1 and 2)SimbadNameSimbad column added by the CDSmeta.idcharSpTMK spectral typesrc.spTypecharDateUT date of observationtime.epoch;obscharFeH[0.6/1.5] 1.2{mu}m FeH_J_ absorption indexspect.indexfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar designationmeta.id;meta.maincharprimaryRef[1003/1111] Discovery referencemeta.ref;pos.frameintr_SpT[1001/1108] SpT referencemeta.ref;pos.frameintCalibA0V star calibrator(s) (other spectral type in parenthesis)meta.idcharSlit[0.3/0.8] Slit widtharcsecspect.line.widthfloatExp[120/6600] Exposure timestime.duration;obs.exposureintAgeDisplay the known ages data for this star (table 3)meta.ref.urlcharK1.1692[-2.2/20.5]? KI 1.1692um equivalent width in {AA} units0.1nmmeta.unit;spect.line.eqWidth;em.IR.Jfloatnullablee_K1.1692[0.02/5]? K1.1692 uncertainty0.1nmstat.errorfloatnullableK1.1778[-0.9/18]? KI 1.1778um equivalent width in {AA} units0.1nmmeta.unit;spect.line.eqWidth;em.IR.Jfloatnullablee_K1.1778[0.02/5.1]? K1.1778 uncertainty0.1nmstat.errorfloatnullableK1.2437[-2.5/9.3]? KI 1.2437um equivalent width in {AA} units0.1nmmeta.unit;spect.line.eqWidth;em.IR.Jfloatnullablee_K1.2437? K1.2437 uncertainty0.1nmstat.errorfloatnullableK1.2529[-1.2/11.2]? KI 1.2529um equivalent width in {AA} units0.1nmmeta.unit;spect.line.eqWidth;em.IR.Jfloatnullablee_K1.2529[0.02/2.1]? K1.2529 uncertainty0.1nmstat.errorfloatnullablee_FeH[0/0.8] FeH uncertaintystat.errorfloatGravGravity scores: K1 K2 K4 FeH (0=high gravity) (1)src.classcharTypeGravity type from this paper (G1)src.classcharpTypeGravity type from A13 (G1)src.classcharBCatDisplay the previous published spectra catalogs (Kirkpatrick+ 2010, J/ApJS/190/100; 2014, J/ApJ/783/122 and Mace+, 2013, J/ApJS/205/6)meta.ref.urlintnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main