J/ApJ/788/40ivo://CDS.VizieR/J/ApJ/788/40doi:10.26093/cds/vizier.17880040CDSTodorov K.O.Luhman K.L.Konopacky Q.M.McLeod K.K.Apai D.Ghez A.M.,Pascucci I.Robberto M.2017-09-04T08:04:08Z2017-07-10T14:10:24ZCDS support team

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

cds-question@unistra.frmultiple-starsdwarf-starslate-type-starsstellar-spectral-typesWe have used WFPC2 on board the Hubble Space Telescope to obtain images of 47 members of the Taurus and Chamaeleon I star-forming regions that have spectral types of M6-L0 (M~0.01-0.1 M_{sun}_). An additional late-type member of Taurus, FU Tau (M7.25+M9.25), was also observed with adaptive optics at Keck Observatory. In these images, we have identified promising candidate companions to 2MASS J04414489+2301513 ({rho}=0.105"/15 AU), 2MASS J04221332+1934392 ({rho}=0.05"/7 AU), and ISO 217 ({rho}=0.03"/5 AU). We reported the first candidate in a previous study, showing that it has a similar proper motion as the primary in images from WFPC2 and Gemini adaptive optics. We have collected an additional epoch of data with Gemini that further supports that result. By combining our survey with previous high-resolution imaging in Taurus, Chamaeleon I, and Upper Sco ({tau}~10 Myr), we measure binary fractions of 14/93=0.15_-0.03_^+0.05^ for M4-M6 (M~0.1-0.3 M_{sun}_) and 4/108=0.04_-0.01_^+0.03^ for >M6 (M<~0.1 M_{sun}_) at separations of >10 AU. Given the youth and low density of these regions, the lower binary fraction at later types is probably primordial rather than due to dynamical interactions among association members. The widest low-mass binaries (>100 AU) also appear to be more common in Taurus and Chamaeleon I than in the field, which suggests that the widest low-mass binaries are disrupted by dynamical interactions at >10 Myr, or that field brown dwarfs have been born predominantly in denser clusters where wide systems are disrupted or inhibited from forming.2014ApJ...788...40Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/788/40CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/AJ/120/479 : Low-mass stars in the Upper Sco association (Ardila+, 2000)J/ApJ/578/914 : Low-mass stars in Taurus (Hartmann, 2002)J/ApJ/645/676 : Spatial distribution of brown dwarfs in TaurusJ/ApJ/684/654 : Low-mass members of Chamaeleon I (Luhman+, 2008)J/ApJ/703/1511 : Wide binaries in Taurus and Upper Sco (Kraus+, 2009)J/ApJ/757/141 : Companion IR detection limits in young associationsJ/MNRAS/418/1231 : New brown dwarfs in upper Sco (Dawson+, 2011)J/ApJ/745/119 : Close companions to young stars. I. ChaI + TauJ/ApJ/746/154 : Improved kinematic parallaxes for Sco-Cen membershttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/788/40https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/788/40http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/788/40https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/788/40https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/788/40http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/788/40GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/788/40/table4 (Late-type Targets of Multiplicity Surveys in Taurus, Cha I, and Upper Sco)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/788/40/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/788/40/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/788/40/table4?GETtext/xml+votable180.050000true63.549504228.19819720.0055555555555555565/270 11088 11090 6/342 350 1029 1031 1033 1037 1039 1040 1042 1043 1047 1050 1051 1052 1054 1061 1063 1069 1073 1074 1075 1078 1079 1084 1114 1115 1159 1168 1169 1170 23533 23549 24201 24221 30729 36956 36957 37128 42962 42985 42986 42987 42988 42989 43000 44311 44317 44341 44356 44358 44359 44365 44367 44372 44376 44378 44385 44388https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/788/40?format=asciiOpticaldefaultJ/ApJ/788/40/table4Late-type Targets of Multiplicity Surveys in Taurus, Cha I, and Upper ScoSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS name (JHHMMSSss+DDMMSSs) (1)meta.id;meta.maincharOtherNameOther source namemeta.idcharSpTypeSpectral typesrc.spTypecharrhoProjected separation (2)arcsecpos.angDistancecharr_rhoReference on rho (3)meta.ref;pos.framechar_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