J/ApJ/745/119ivo://CDS.VizieR/J/ApJ/745/119doi:10.26093/cds/vizier.17450119CDSNguyen D.C.Brandeker A.van Kerkwijk M.H.Jayawardhana R.2017-10-02T19:28:51Z2013-09-05T07:28:42ZCDS support team

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

cds-question@unistra.frspectroscopic-binary-starsyoung-stellar-objectsradial-velocitystellar-spectral-typesspectroscopyWe present the results of a multiplicity survey of 212 T Tauri stars in the Chamaeleon I and Taurus-Auriga star-forming regions, based on high-resolution spectra from the Magellan Clay 6.5m telescope. From these data, we achieved a typical radial velocity (RV) precision of ~80m/s with slower rotators yielding better precision, in general. For 174 of these stars, we obtained multi-epoch data with sufficient time baselines to identify binaries based on RV variations. We identified eight close binaries and four close triples, of which three and two, respectively, are new discoveries. The spectroscopic multiplicity fractions we find for Chamaeleon I (7%) and Taurus-Auriga (6%) are similar to each other, and to the results of field star surveys in the same mass and period regime. However, unlike the results from imaging surveys, the frequency of systems with close companions in our sample is not seen to depend on primary mass. Additionally, we do not find a strong correlation between accretion and close multiplicity. This implies that close companions are not likely the main source of the accretion shut down observed in weak-lined T Tauri stars. Our results also suggest that sufficient RV precision can be achieved for at least a subset of slowly rotating young stars to search for hot Jupiter planets.2012ApJ...745..119Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/745/119CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/703/1511 : Wide binaries in Taurus and Upper Sco (Kraus+, 2009)J/ApJ/703/1964 : Spectra of three nearby star-forming regions (Furlan+, 2009)J/PASJ/60/209 : Faint companions around YSOs in TMC (Itoh+, 2008)J/ApJ/684/654 : Low-mass members of Chamaeleon I (Luhman+, 2008)J/ApJ/662/413 : Wide multiplicity in 3 associations with 2MASS (Kraus+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/745/119https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/745/119http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/745/119https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/745/119https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/745/119http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/745/119GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/745/119/table2 (Measurements of stars without close companions in Cha I and Tau-Aur)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/745/119/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/745/119/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/745/119/table2?GETtext/xml+votable180.050000true164.126875-77.194250.005555555555555556Cone search capability for table J/ApJ/745/119/table3 (Measurements of stars with close companions in Cha I and Tau-Aur (28 binaries))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/745/119/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/745/119/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/745/119/table3?GETtext/xml+votable180.050000true167.2988333-77.48680560.0055555555555555565/292 5887 9239 6/324 325 326 331 332 336 342 347 350 358 368 380 473 1027 1029 1030 1031 1039 1040 1042 1048 1050 1051 1052 1054 1055 1066 1067 1073 1074 1075 1080 1081 1083 1098 1099 1111 1114 1115 1123 1134 1136 1152 1155 1156 1159 1165 1181 1182 1199 1207 23517 23518 23533 23542 23543 24105 24107 24193 24195 24201 24203 24204 24205 24207 24219 24222 24234 24237 24238 24249 24294 24300 37128https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/745/119?format=asciiOpticaldefaultJ/ApJ/745/119/table2Measurements of stars without close companions in Cha I and Tau-AurSimbadNameSimbad column added by the CDSmeta.idcharHa[53/647]? H{alpha} 10% width (G1)km/sspect.line.widthintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegRegion name (ChaI or Tau-Aur)meta.id.parentcharNameObject namemeta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainSpTMK spectral typesrc.spTypecharTTS[?cw] T Tauri classification (c=classical TTauri star, w=weak-lined, ?=unknown)meta.code.classchare_Ha[3/98]? H{alpha} width scatter (G2)km/sstat.errorintnullablef_Ha[a] a=absorp.meta.codecharvsini[0.8/127] Rotational velocity (G1)km/sphys.veloc.rotatfloate_vsini[0.11/10] vsini uncertainty (G3)km/sstat.error;phys.veloc.rotatfloatRV[3.6/32.1] Radial velocitykm/sphys.veloc;pos.heliocentricfloate_RV[0.006/3] RV uncertaintykm/sstat.errorfloatf_RV[d] Possible non-member (1)meta.codecharl_SigRVLimit flag on SigRVmeta.code.errorcharSigRV[0.01/12]? Weighted standard deviation of RV (2)km/sstat.stdevfloatnullablel_SigNLimit flag on SigNmeta.code.errorcharSigN[0.01/13]? Systematic noise of RV (2)km/sstat.stdevfloatnullableNobs[1/7] Number of observationsmeta.numberintFigCorresponding figure number (column added by CDS) (G4)meta.bib.figchar2MCross-match with 2MASS (Cat. II/246) within 0.5"meta.ref.urlintnullableJ/ApJ/745/119/table3Measurements of stars with close companions in Cha I and Tau-Aur (28 binaries)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSBTSpectroscopic Binary type (SB1, SB2, SB3, ?)src.classcharn_SBT[d] d = long periodmeta.notecharRegRegion name (Cha or Tau)meta.id.parentcharNameObject namemeta.id;meta.maincharm_Name[ABCab12 ] Componentmeta.code.multipcharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainSpTMK spectral typesrc.spTypecharTTST Tauri classification (c=classical, w=weak-lined, ?meta.code.classcharHa[101/600]? H{alpha} 10% width (G1)km/sspect.line.widthintnullablee_Ha[8/126]? H{alpha} width scatter (G2)km/sstat.errorintnullablef_Ha[a] a=Absorp.meta.codecharNobs[1/7]? Number of observationsmeta.numberintnullablevsini[7.4/94.1] Rotational velocity (G1)(3)km/sphys.veloc.rotatfloate_vsini[0.12/15] vsini uncertainty (G3)km/sstat.error;phys.veloc.rotatfloatFR[0.07/1]? Flux ratio between the companion and the primary star (see section 3.2)phot.flux;arith.ratiofloatnullablee_FR[0.005/0.4]? FR uncertaintystat.errorfloatnullableFigCorresponding figure number (column added by CDS) (G4)meta.bib.figchar2MCross-match with 2MASS (Cat. II/246) within 0.5"meta.ref.urlintnullable