J/AJ/154/112ivo://CDS.VizieR/J/AJ/154/112doi:10.26093/cds/vizier.51540112CDSKellogg K.Metchev S.Miles-Paez P.A.Tannock M.E.2019-12-17T12:53:29Z2018-02-07T12:53:14ZCDS support team

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

cds-question@unistra.frl-dwarfsdwarf-starsstellar-spectral-typesinfrared-astronomyspectroscopyWe present the final results from a targeted search for brown dwarfs with unusual near-infrared colors. From a positional cross-match of the Sloan Digital Sky Survey (SDSS), 2-Micron All-Sky Survey (2MASS), and Wide-Field Infrared Survey Explorer (WISE) catalogs, we have identified 144 candidate peculiar L and T dwarfs. Spectroscopy confirms that 20 of the objects are peculiar or are candidate binaries. Of the 420 objects in our full sample 9 are young (<~200Myr; 2.1%) and another 8 (1.9%) are unusually red, with no signatures of youth. With a spectroscopic J-K_s_ color of 2.58+/-0.11mag, one of the new objects, the L6 dwarf 2MASS J03530419+0418193, is among the reddest field dwarfs currently known and is one of the reddest objects with no signatures of youth known to date. We have also discovered another potentially very-low-gravity object, the L1 dwarf 2MASS J00133470+1109403, and independently identified the young L7 dwarf 2MASS J00440332+0228112, which was first reported by Schneider and collaborators. Our results confirm that signatures of low gravity are no longer discernible in low to moderate resolution spectra of objects older than ~200Myr. The 1.9% of unusually red L dwarfs that do not show other signatures of youth could be slightly older, up to ~400Myr. In this case a red J-K_s_ color may be more diagnostic of moderate youth than individual spectral features. However, its is also possible that these objects are relatively metal-rich, and thus have enhanced atmospheric dust content.2017AJ....154..112Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/154/112CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)II/328 : AllWISE Data Release (Cutri+ 2013)V/139 : SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/ApJ/810/158 : M,L,T dwarfs parameters and SEDs (Filippazzo+, 2015)J/ApJ/794/143 : New SpeX Observations of M7-L6 Dwarfs (Bardalez+, 2014)J/AJ/147/34 : SpeX library of L-type dwarfs (Schneider+, 2014)J/PASP/125/809 : New nearby M, L, and T dwarfs (Thompson+, 2013)J/ApJS/205/6 : T dwarf population revealed by WISE (Mace+, 2013)J/ApJ/710/1142 : SpeX spectroscopy of low mass binaries. I. (Burgasser+, 2010)J/AJ/137/1 : PMs and astrometry of late-type dwarfs (Faherty+, 2009)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/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)J/AJ/127/3553 : Photometry and spectroscopy for L and T dwarfs (Knapp+, 2004)J/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)J/ApJ/564/421 : Spectra of T dwarfs. I. (Burgasser+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/154/112https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/154/112http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/154/112https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/154/112https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/154/112http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/154/112GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/154/112/table3 (Results from spectroscopic classification and synthetic photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/112/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/112/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/112/table3?GETtext/xml+votable180.050000true1.73133332.61044440.005555555555555556Cone search capability for table J/AJ/154/112/table1 (Infrared Telescope Facility/SpeX (IRTF/SpeX) observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/112/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/112/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/112/table1?GETtext/xml+votable180.050000true1.73133332.61044440.005555555555555556Cone search capability for table J/AJ/154/112/table2 (Gemini/Gemini Near-Infrared Spectrograph (Gemini/GNIRS) observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/112/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/112/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/112/table2?GETtext/xml+votable180.050000true25.360458310.02608330.005555555555555556Cone search capability for table J/AJ/154/112/table4 (Unknown object properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/112/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/112/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/112/table4?GETtext/xml+votable180.050000true29.548833332.53369440.0055555555555555566/597 738 1669 1689 1781 2064 2164 2189 2258 2425 2653 2654 2655 2752 4312 4499 4727 5159 5761 5957 6053 6088 6104 6183 6499 7243 7249 7275 8452 8476 8633 8693 8947 9083 9209 9393 9474 9565 9721 9926 10467 10471 10476 10503 10510 10730 10815 10871 10902 11007 11318 11553 12384 13400 17226 17257 17613 17622 17655 17800 17904 17992 18031 18121 18180 18284 18335 18347 18817 18869 18924 19224 19337 19359 19443 19461 19541 19565 19655 19794 20077 20326 20334 22390 22728 22876 22949 23126 23257 23444 23637 23638 24329 25238 25506 25928 26213 26311 26346 27090 27384 28045 28303 28394 30821 30956 31484 32257 32443 32461 36343 36524 448963.830199579824256e-20 2.3647030891844645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/154/112?format=asciiInfrareddefaultJ/AJ/154/112/table3Results from spectroscopic classification and synthetic photometry2sigObject greater than 2{sigma} outlier in color (3)meta.codechar1sigObject greater than 1{sigma} outlier in color (3)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharprimaryGNIRSNIR spectroscopic observations using the Gemini Near-Infrared Spectrograph (GNIRS) instrument on the Gemini North telescope (table2)meta.numberintnullableIRTFIndicates near-infrared spectroscopic observations using the SpeX instrument on the NASA Infrared Telescope Facility (IRTF) in table1meta.numberintnullableUnknwindicates an Unknown object (table4)meta.codecharnullableType[1/5] Candidate type (1)src.classintSpTInfrared Spectral typesrc.spTypecharn_SpTNote on SpT (interpretation of spectrum)meta.notecharf_z-J[ab] Flag on z-J when synthetic color calculations are limited by spectrum (2)meta.codecharz-J[0.9/4.4]? Synthetic z-J color index computed from spectrummagphot.color;em.opt;em.IRfloatnullablee_z-J[0.03/0.16]? Uncertainty in z-Jmagstat.errorfloatnullableJ-H[0.3/2.7] Synthetic J-H color index computed from spectrummagphot.color;em.IR.J;em.IR.Hfloate_J-H[0.03/0.3] Uncertainty in J-Hmagstat.error;phot.color;em.IR.JfloatJ-Ks[0.3/3.7] Synthetic J-Ks color index computed from spectrummagphot.color;em.IR.J;em.IR.Kfloate_J-Ks[0.02/0.26] Uncertainty in J-Ksmagstat.error;phot.color;em.IR.JfloatSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlchar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharSDSSDisplay the SDSS DR9 (Adelman-McCarthy et al. 2012, Cat. V/139), and SDSS DR12 (Alam et al. 2015, Cat. V/147) data within 5''meta.ref.urlcharAllWISEDisplay the AllWISE data (Cutri et al. 2013, Cat. II/328) within 5''meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPosition from 2MASS name (right ascension part)degpos.eq.ra;meta.main_DEPosition from 2MASS name (declination part)degpos.eq.dec;meta.mainJ/AJ/154/112/table1Infrared Telescope Facility/SpeX (IRTF/SpeX) observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharf_2MASS[ab] Flag for independent reports (a or b) (G1)meta.codecharDateUT observation datetime.epoch;obsnullableJmag[14.51/17.56] 2MASS J band magnitudemagphot.mag;em.IR.JfloatSlit[0.8/1.6] Slit widtharcsecspect.line.widthfloatExp[10/76] Exposure timemintime.duration;obs.exposureintA0Name of A0 type calibratormeta.id.assocchar_RAPosition from 2MASS name (right ascension part)degpos.eq.ra;meta.main_DEPosition from 2MASS name (declination part)degpos.eq.dec;meta.mainJ/AJ/154/112/table2Gemini/Gemini Near-Infrared Spectrograph (Gemini/GNIRS) observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharf_2MASS[a] Flag for independent reports (a) (G1)meta.codecharDateUT observation datetime.epoch;obsnullableJmag[15.9/17.4] 2MASS J band magnitudemagphot.mag;em.IR.JfloatExp[40/124] Exposure timemintime.duration;obs.exposureintA0Name of A0 type Calibratormeta.id.assocchar_RAPosition from 2MASS name (right ascension part)degpos.eq.ra;meta.main_DEPosition from 2MASS name (declination part)degpos.eq.dec;meta.mainJ/AJ/154/112/table4Unknown object propertiesTelTelescope+Instrument setupinstr.setupcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharSurveySurvey in which identified (P1=Kellogg et al. 2015AJ....150..182K or P2=this work)meta.notecharzmag[18.8/20.5] SDSS z band magnitudemagphot.mag;em.opt.Ifloate_zmag[0.04/0.16] Uncertainty in zmagmagstat.error;phot.mag;em.opt.IfloatJmag[15.8/17.5] 2MASS J band magnitudemagphot.mag;em.IR.Jfloate_Jmag[0.07/0.3] Uncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatHmag[13.9/16.5] 2MASS H band magnitudemagphot.mag;em.IR.Hfloate_Hmag[0.03/0.3] Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatKsmag[13/15.6] 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloate_Ksmag[0.02/0.2] Uncertainty in Ksmagmagstat.error;phot.mag;em.IR.KfloatW1mag[12/15.4] WISE W1 band magnitudemagphot.mag;em.IR.3-4umfloate_W1mag[0.02/0.04] Uncertainty in W1magmagstat.error;phot.magfloatW2mag[11.1/15] WISE W2 band magnitudemagphot.mag;em.IR.4-8umfloate_W2mag[0.02/0.07] Uncertainty in W2magmagstat.error;phot.magfloat_RAPosition from 2MASS name (right ascension part)degpos.eq.ra;meta.main_DEPosition from 2MASS name (declination part)degpos.eq.dec;meta.main