J/ApJ/757/141ivo://CDS.VizieR/J/ApJ/757/141doi:10.26093/cds/vizier.17570141CDSKraus A.L.Hillenbrand L.A.2017-09-22T16:16:13Z2014-07-16T09:32:29ZCDS support team

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

cds-question@unistra.frstellar-massesmultiple-starsinfrared-photometryThe frequency and properties of multiple star systems offer powerful tests of star formation models. Multiplicity surveys over the past decade have shown that binary properties vary strongly with mass, but the functional forms and the interplay between frequency and semimajor axis remain largely unconstrained. We present the results of a large-scale survey of multiplicity at the bottom of the initial mass function in several nearby young associations, encompassing 78 very low mass members observed with Keck laser guide star adaptive optics. Our survey confirms the overall trend observed in the field for lower-mass binary systems to be less frequent and more compact, including a null detection for any substellar binary systems with separations wider than ~7AU. Combined with a Bayesian re-analysis of existing surveys, our results demonstrate that the binary frequency and binary separations decline smoothly between masses of 0.5M_{sun}_ and 0.02M_{sun}_, though we cannot distinguish the functional form of this decline due to a degeneracy between the total binary frequency and the mean binary separation. We also show that the mass ratio distribution becomes progressively more concentrated at q~1 for declining masses, though a small number of systems appear to have unusually wide separations and low-mass ratios for their mass. Finally, we compare our results to synthetic binary populations generated by smoothed particle hydrodynamic simulations, noting the similarities and discussing possible explanations for the differences.2012ApJ...757..141Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/757/141CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/MNRAS/431/3222 : UKIDSS GCS Upper Sco members (Lodieu, 2013)J/MNRAS/418/1231 : New brown dwarfs in upper Sco (Dawson+, 2011)J/ApJS/196/4 : New young star candidates in Taurus-Auriga (Rebull+, 2011)J/ApJ/731/8 : Multiple star formation in Taurus-Auriga (Kraus+, 2011)J/AJ/139/1338 : UV-selected stars in Tau and Upper Sco (Findeisen+, 2010)J/ApJ/704/531 : The coevality of young binary systems (Kraus+, 2009)J/ApJ/703/1511 : Wide binaries in Taurus and Upper Sco (Kraus+, 2009)J/ApJ/688/377 : Low-mass objects in Upper Scorpius. II. (Slesnick+, 2008)J/ApJ/662/413 : 2MASS survey of multiplicity in 3 associations (Kraus+, 2007)J/MNRAS/374/372 : ZYJHK photometry in Upper Sco (Lodieu+, 2007)J/MNRAS/373/95 : ZYJHK survey of Upper Sco association (Lodieu+, 2006)J/ApJ/651/L49 : Upper Sco OB association IRAC observations (Carpenter+, 2006)J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)J/ApJ/645/676 : Spatial distribution of brown dwarfs in Taurus (Luhman+, 2006)J/A+A/446/485 : New very low-mass members in Taurus (Guieu+, 2006)J/AJ/132/2665 : QUEST2 BRI photometry of Taurus-Auriga PMS (Slesnick+, 2006)J/AJ/131/3016 : Low-mass objects in Upper Scorpius (Slesnick+, 2006)J/A+A/416/555 : Brown Dwarfs in ChaI Dark Cloud (Lopez-Marti+ 2004)J/ApJ/602/816 : Chamaeleon I star-forming region census (Luhman, 2004)J/AJ/126/1526 : IR photometry of ultracool dwarfs (Bouy+, 2003)J/AJ/124/404 : USco OB association Lithium survey. II. (Preibisch, 2002)J/A+A/356/541 : T Tauri stars in the Sco-Cen OB association (Koehler+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/757/141https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/757/141http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/757/141https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/757/141https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/757/141http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/757/141GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/757/141/table1 (Observed sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/757/141/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/757/141/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/757/141/table1?GETtext/xml+votable180.050000true59.791041720.16008330.005555555555555556Cone search capability for table J/ApJ/757/141/table7 (Companion detection limits from previous surveys)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/757/141/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/757/141/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/757/141/table7?GETtext/xml+votable180.050000true164.4258333-76.993250.0055555555555555565/270 9239 11079 11088 11089 11090 11094 11096 11097 6/337 342 350 365 1029 1031 1033 1037 1039 1040 1042 1043 1047 1050 1051 1052 1054 1061 1069 1073 1074 1075 1078 1079 1084 1114 1115 1126 1132 1136 1156 1159 1164 1168 1169 1170 1180 23533 23548 23549 24188 24191 24198 24201 24221 24232 24262 24281 24294 24295 24300 30729 37128 42934 42962 42976 42979 42981 42982 42985 42986 42987 42988 42989 42991 42994 43000 43001 43002 43004 43005 44297 44304 44305 44307 44308 44309 44311 44315 44341 44365 44366 44367 44368 44372 44397 44400 44401 44402 44404 44408 44483https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/757/141?format=asciiInfrareddefaultJ/ApJ/757/141/table1Observed samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion identifier (Taurus or Upper Sco)meta.id;obs.fieldcharNameTarget identifiermeta.id;meta.maincharprimaryNcNumber of candidate companions for this star (table3)meta.ref.urlintnullableNoNumber of observations for this star (table2)meta.ref.urlintnullableLCompanion detection limits (tables 4 and 7)meta.ref.urlintnullableRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainSpTMK spectral typesrc.spTypecharMass[0.01/0.6]? MasssolMassphys.massfloatnullableKmag[7.6/14.5] 2MASS K-band magnitudemagphot.mag;em.IR.KfloatRmag[10/19] USNO-B1 R-band magnitude (R_TT_)magphot.mag;em.opt.RfloatdTT[0/54]? USNO-B1 distance to each star's tip-tilt (d_TT_)arcsecpos;arith.difffloatnullableRef[1/3]? Reference (2)meta.ref;pos.frameintnullableKHDisplay the Kraus & Hillenbrand 2007 data (J/ApJ/662/413)meta.ref.urlintnullable2MDisplay the 2MASS data within 3" (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharUSNODisplay the USNO-B1 data within 3" (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharJ/ApJ/757/141/table2ObservationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget identifiermeta.id;meta.maincharf_Name[a] a: Observation also includes 2M04554801+3028050 in the same fieldmeta.codecharEpochJulian date; JD-2450000dtime.epochintModeObservation modeinstr.setupcharTint[30/850] Integration timestime.epochintFWHMTypical point-spread function (PSF) FWHMmasinstr.det.psfcharFElonFractional elongation%instr.det.psfcharJ/ApJ/757/141/table3Candidate companions to young stars and brown dwarfsN[1/34] Number of measuresmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion identifier (Tau or USco)meta.id;obs.fieldcharNameTarget identifier (3)meta.id;meta.maincharCompCompanion identification (1)meta.code.multipcharr_CompPreviously identified as candidate companion reference (2)meta.ref;pos.framecharEpochJulian Date; JD-2450000dtime.epochintSep[48/8878] Companion separationmaspos.angDistanceinte_Sep[1/25] Sep uncertaintymasstat.errorintPA[0.2/351] Companion position angledegpos.posAngfloate_PA[0.002/1.7] PA uncertaintydegstat.errorfloatDK'[0/8] The {Delta}K' flux ratiomagphot.flux;arith.ratiofloate_DK'[0.003/0.2] DK' uncertaintymagstat.errorfloatJ/ApJ/757/141/table4Companion detection limitsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion identifier (Taurus or Upper Sco)meta.id;obs.fieldcharNameTarget identifiermeta.id;meta.maincharDK40? The {Delta}K' flux ratio at 40mas separationmagphot.flux;arith.ratiofloatnullableDK45? The {Delta}K' flux ratio at 45mas separationmagphot.flux;arith.ratiofloatnullableDK50? The {Delta}K' flux ratio at 50mas separationmagphot.flux;arith.ratiofloatnullableDK60? The {Delta}K' flux ratio at 60mas separationmagphot.flux;arith.ratiofloatnullableDK80? The {Delta}K' flux ratio at 80mas separationmagphot.flux;arith.ratiofloatnullableDK100? The {Delta}K' flux ratio at 100mas separationmagphot.flux;arith.ratiofloatnullableDK120? The {Delta}K' flux ratio at 120mas separationmagphot.flux;arith.ratiofloatnullableDK150? The {Delta}K' flux ratio at 150mas separationmagphot.flux;arith.ratiofloatnullableDK200? The {Delta}K' flux ratio at 200mas separationmagphot.flux;arith.ratiofloatnullableDK300? The {Delta}K' flux ratio at 300mas separationmagphot.flux;arith.ratiofloatnullableDK400The {Delta}K' flux ratio at 400mas separationmagphot.flux;arith.ratiofloatDK500The {Delta}K' flux ratio at 500mas separationmagphot.flux;arith.ratiofloatDK750The {Delta}K' flux ratio at 750mas separationmagphot.flux;arith.ratiofloatDK1000The {Delta}K' flux ratio at 1arcsec separationmagphot.flux;arith.ratiofloatDK2000The {Delta}K' flux ratio at 2arcsec separationmagphot.flux;arith.ratiofloatJ/ApJ/757/141/table7Companion detection limits from previous surveysSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion identifier (Cha-I, Taurus or Upper Sco)meta.id;obs.fieldcharNameTarget identifiermeta.id;meta.maincharPStar properties if studied in this paper (table1)meta.ref.urlintnullableRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainMass[0.01/0.5] Primary star's masssolMassmeta.idfloatq0.5? Mass ratio at log({rho})=0.5 (1)phys.mass;arith.ratiofloatnullableq0.6? Mass ratio at log({rho})=0.6 (1)phys.mass;arith.ratiofloatnullableq0.7? Mass ratio at log({rho})=0.7 (1)phys.mass;arith.ratiofloatnullableq0.8? Mass ratio at log({rho})=0.8 (1)phys.mass;arith.ratiofloatnullableq0.9? Mass ratio at log({rho})=0.9 (1)phys.mass;arith.ratiofloatnullableq1.0? Mass ratio at log({rho})=1.0 (1)phys.mass;arith.ratiofloatnullableq1.1? Mass ratio at log({rho})=1.1 (1)phys.mass;arith.ratiofloatnullableq1.2? Mass ratio at log({rho})=1.2 (1)phys.mass;arith.ratiofloatnullableq1.3? Mass ratio at log({rho})=1.3 (1)phys.mass;arith.ratiofloatnullableq1.4? Mass ratio at log({rho})=1.4 (1)phys.mass;arith.ratiofloatnullableq1.6? Mass ratio at log({rho})=1.6 (1)phys.mass;arith.ratiofloatnullableq1.8? Mass ratio at log({rho})=1.8 (1)phys.mass;arith.ratiofloatnullableq2.1? Mass ratio at log({rho})=2.1 (1)phys.mass;arith.ratiofloatnullableq2.4? Mass ratio at log({rho})=2.4 (1)phys.mass;arith.ratiofloatnullableq2.7? Mass ratio at log({rho})=2.7 (1)phys.mass;arith.ratiofloatnullableq3.0? Mass ratio at log({rho})=3.0 (1)phys.mass;arith.ratiofloatnullableq3.6? Mass ratio at log({rho})=3.6 (1)phys.mass;arith.ratiofloatnullableRefReference(s) (2)meta.ref;pos.framecharKHDisplay the Kraus & Hillenbrand 2007 data (J/ApJ/662/413)meta.ref.urlintnullable