J/ApJ/934/178ivo://CDS.VizieR/J/ApJ/934/178doi:10.26093/cds/vizier.19340178CDSAshraf A.Bardalez Gagliuffi D.C.Manjavacas E.Vos J.M.Mechmann C.,Faherty J.K.2024-11-06T20:26:22Z2024-08-19T09:56:58ZCDS support team

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

cds-question@unistra.frbrown-dwarfsstellar-spectral-typesinfrared-astronomyspectroscopyl-dwarfsinfrared-photometryvariable-starsWe present a technique to identify spectrophotometrically variable L7-T3 brown dwarfs with single-epoch, low-resolution, near-infrared SpeX spectra. We calculated spectral indices on known variable brown dwarfs and used them to select 11 index-index parameter spaces where known variables can be distinguished from the rest of the general population of brown dwarfs. We find 62 candidate variables, 12 of which show significant variability amplitude in independent photometric monitoring surveys. This technique constitutes the first formal method to identify a time-dependent effect such as variability from peculiarities in their integrated light spectra. This technique will be a useful tool to prioritize targets for future photometric and spectroscopic monitoring in the era of the James Webb Space Telescope and 30m-class telescopes.2022ApJ...934..178Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/934/178CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/564/421 : Spectra of T dwarfs. I. (Burgasser+, 2002)J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)J/AJ/126/1526 : IR photometry of ultracool dwarfs (Bouy+, 2003)J/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)J/AJ/127/3553 : JHK phot. and spectroscopy for L and T dwarfs (Knapp+, 2004)J/ApJ/637/1067 : Near-IR spectral classif. of T dwarfs (Burgasser+, 2006)J/AJ/131/2722 : New L and T dwarfs from the SDSS (Chiu+, 2006)J/AJ/132/891 : Binaries among nearby L dwarfs (Reid+, 2006)J/AJ/133/439 : Luminosity function of M7-L8 ultracool dwarfs (Cruz+, 2007)J/AJ/134/1162 : 11 new T dwarfs in 2MASS (Looper+, 2007)J/AJ/133/2258 : Activity and kinematics of ultracool dwarfs (Schmidt+, 2007)J/ApJ/689/1295 : Lithium test implications for BDs (Kirkpatrick+, 2008)J/ApJ/676/1281 : L and T dwarfs in 2MASS/SDSS (Metchev+, 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/710/1142 : SpeX spectrosc. of low mass binaries. I. (Burgasser+, 2010)J/MNRAS/402/1380 : Rot. velocities in Pleiades and {alpha}Per (Jackson+, 2010)J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)J/AJ/142/77 : New T dwarfs identified in Pan-STARRS 1 (Deacon+, 2011)J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)J/ApJS/201/19 : Hawaii Infrared Parallax Program. I. (Dupuy+, 2012)J/AJ/144/8 : Sp. of ~100 G/K/M-type Sco-Cen complex members (Song+, 2012)J/MNRAS/430/1171 : Sub-stellar birth rate from UKIDSS (Day-Jones+, 2013)J/ApJS/205/6 : T dwarf population revealed by WISE (Mace+, 2013)J/PASP/125/809 : New nearby M, L, and T dwarfs (Thompson+, 2013)J/ApJ/794/143 : New SpeX Observations of M7-L6 Dwarfs (Bardalez+, 2014)J/ApJ/783/121 : BANYAN II. Nearby young assoc. cand. members (Gagne+, 2014)J/ApJ/787/126 : WISE reduced PMs and spectral types (Luhman+, 2014)J/AJ/147/34 : SpeX library of L-type dwarfs (Schneider+, 2014)J/ApJ/814/118 : L/T dwarfs search with PS1 & WISE. II. (Best+, 2015)J/ApJ/810/158 : M,L,T dwarfs fundamental param. and SEDs (Filippazzo+, 2015)J/ApJ/798/73 : BANYAN All-Sky Survey cat. V. Nearby YMGs (Gagne+, 2015)J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)J/ApJ/833/96 : Hawaii IR parallax prog. II. Ultracool dwarfs (Liu+, 2016)J/ApJ/817/112 : NEOWISE/AllWISE high PM objects (Schneider+, 2016)J/AJ/154/112 : NIR spectroscopy of new L & T dwarf cand. (Kellogg+, 2017)J/ApJ/856/23 : BANYAN. XI. The BANYAN {Sigma} algorithm (Gagne+, 2018)J/AJ/155/265 : Solar neighborhood. XLIV. RECONS discoveries (Henry+, 2018)J/ApJ/883/205 : Ultracool SpeXtroscopic survey. I. M7-L5 (Bardalez+, 2019)J/A+A/629/A145 : L9-T3.5 brown dwarfs light curves (Eriksson+, 2019)J/AJ/157/101 : Cloud Atlas: HST/WFC3 NIR sp. library (Manjavacas+, 2019)J/AJ/159/257 : Hawaii IR parallax prog. IV. L0-T8 BDs (Best+, 2020)J/AJ/160/38 : Spitzer variability detections of brown dwarfs (Vos+, 2020)J/AJ/161/42 : Volume-limited sample of cool dwarfs. I. L0-T8 (Best+, 2021)J/ApJS/253/7 : A full-sky census of BDs within 20pc (Kirkpatrick+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/934/178https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/934/178http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/934/178https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/934/178https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/934/178http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/934/178GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/934/178/table1 (Confirmed variability sources used as benchmarks in our study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/178/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/178/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/178/table1?GETtext/xml+votable180.050000true11.751611168.06510190.005555555555555556Cone search capability for table J/ApJ/934/178/table4 (Variability candidates with spectral types between L7-T3)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/178/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/178/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/178/table4?GETtext/xml+votable180.050000true4.181837523.07395830.005555555555555556Cone search capability for table J/ApJ/934/178/tablea1 (Complete spectral run through each index-index correlation)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/178/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/178/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/178/tablea1?GETtext/xml+votable180.050000true1.5952939-13.3306450.005555555555555556Cone search capability for table J/ApJ/934/178/tablea2 (L7-T3 dwarf spectral binary candidates from our index-selection technique)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/934/178/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/934/178/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/934/178/tablea2?GETtext/xml+votable180.050000true71.87665-12.27098330.0055555555555555560/https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/934/178?format=asciiInfrareddefaultJ/ApJ/934/178/table1Confirmed variability sources used as benchmarks in our studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource Namemeta.id;meta.maincharprimarySpT-NIRSpectral type, SpeX/NIRsrc.spType;em.IR.NIRcharYoung?[YN] Youth indicatormeta.codecharRef1? Reference, Optical SpT (see refs.dat file)meta.ref;em.optintnullableRef2[3/23]? Reference, Youth (see refs.dat file)meta.refintnullableRef3Reference(s), Variability (see refs.dat file)meta.ref;src.varchar_DEPositions from Simbad (declination part)degpos.eq.dec;meta.mainSimbadNameSimbad column added by the CDSmeta.idcharnullableONameOther Namemeta.idcharSpT-OptSpectral type, Opticalsrc.spType;em.optchar_RAPositions from Simbad (right ascension part)degpos.eq.ra;meta.mainJ/ApJ/934/178/table4Variability candidates with spectral types between L7-T3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSubset[1/2] Subset: 1) strong; 2) weakmeta.codeintf_NameFlag on Name (1)meta.code;meta.idcharProb1[49/100]? BANYAN {Sigma} probability of belonging to the young moving group 1%stat.probabilityfloatnullableProb2? BANYAN {Sigma} probability of belonging to the young moving group 2%stat.probabilityintnullableRef1? Reference, Youth (see refs.dat file)meta.refintnullableRef2[43/60]? Reference, Variability (see refs.dat file)meta.refintnullable_RAPositions from Simbad of Name (right ascension part)degpos.eq.ra;meta.main_DEPositions from Simbad of Name (declination part)degpos.eq.dec;meta.mainSpTSpeX-based spectral classificationsrc.spTypecharNameSource Namemeta.id;meta.maincharprimaryYMG1Young moving group 1 (2)meta.id.parentcharYMG2Young moving group 2 (2)meta.id.parentcharn_Prob1[*] *=no measurement of parallaxmeta.notecharFilterVariability filterssrc.var;instr.filtercharAmpVariability Amplitude(s)%src.var.amplitudecharRef3Reference(s), Spectral binary (see refs.dat file)meta.refcharSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/ApJ/934/178/tablea1Complete spectral run through each index-index correlationSpTSpeX-based Spectral Typesrc.spTypecharYouth[0/1] Index, Youthspect.indexintI2[0/1] Index, H2O-J vs H-bump (1)spect.indexintI3[0/1] Index, CH4-J vs. CH4 -H (1)spect.indexintI4[0/1] Index, CH4-J vs. H-bump (1)spect.indexintI5[0/1] Index, CH4-H vs. H2 O-K (1)spect.indexintI6[0/1] Index, CH4-H vs. CH4-K (1)spect.indexintI7[0/1] Index, CH4-H vs. H-dip (1)spect.indexintI8[0/1] Index, CH4-H vs. J-curve (1)spect.indexintI9[0/1] Index, H2O-K vs. H-bump (1)spect.indexintI10[0/1] Index, H-dip vs. K-slope (1)spect.indexintI11[0/1] Index, H-dip vs. H-bump (1)spect.indexint_RAPositions from Simbad or Name (right ascension part)degpos.eq.ra;meta.main_DEPositions from Simbad or Name (declination part)degpos.eq.dec;meta.mainSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource Namemeta.id;meta.maincharprimaryI1[0/1] Index, H2O-J vs. CH4-H (1)spect.indexintTotal[0/11] Total Indexspect.indexintJ/ApJ/934/178/tablea2L7-T3 dwarf spectral binary candidates from our index-selection techniqueNameSource namemeta.id;meta.maincharprimaryTotal[2/6] Totalspect.indexint_DEPositions from Simbad of Name (declination part)degpos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSubset[1/3] Subset (1)meta.codeintSpTSpeX-based Spectral Typesrc.spTypecharl_JmagLimit flag on Jmagmeta.code.error;phot.mag;em.IR.JcharJmag[11.5/18] J-band magnitudephot.mag;em.IR.Jfloate_Jmag[0/0.3]? Uncertainty in Jmagstat.error;phot.mag;em.IR.Jfloatnullablel_KmagLimit flag on Kmagmeta.code.error;phot.mag;em.IR.KcharKmag[9.5/17.1]? K-band magnitudephot.mag;em.IR.Kfloatnullablee_Kmag[0/0.31]? Uncertainty in Kmagstat.error;phot.mag;em.IR.KfloatnullableSNR[4/133] Signal-to-noise ratiostat.snrfloatRef1[62/98] Reference, spectrum (see refs.dat file)meta.refintRef2Reference, Spectral binary candidate (see refs.dat file)meta.refintRef3? Reference, Confirmed binarity/variability (see refs.dat file)meta.refintnullable_RAPositions from Simbad of Name (right ascension part)degpos.eq.ra;meta.mainSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/ApJ/934/178/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference codemeta.refintBibCodeBibcode of the referencemeta.bib.bibcodecharCommCommentmeta.notecharAuthFirst author's name(s)meta.bib.authorchar