J/A+A/446/485ivo://CDS.VizieR/J/A+A/446/485doi:10.26093/cds/vizier.34460485CDSGuieu S.Dougados CMonin J-LMagnier E.Martin E.L2017-06-29T08:55:40Z2006-02-10T23:03:25ZCDS support team

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

cds-question@unistra.frm-starsdwarf-starsinfrared-photometryWe have performed a large scale optical survey of the Taurus cloud, covering a total area of 28deg^2^, and encompassing the densest parts of the cloud as well as their surroundings, down to a mass detection limit of 15 Jupiter masses. We present the optical spectroscopic follow-up observations of 97 photometrically selected potential new low-mass Taurus members, of which 27 are strong late-M spectral type SpType<M4V candidates. We derive spectral types, visual absorption and luminosity class estimates and discuss our criteria to assess Taurus membership. These observations reveal 5 new VLM Taurus members and 12 new brown dwarfs. Combining our observations with previously published results, we derive an updated substellar to stellar ratio in Taurus of Rss=0.23+/-0.05. This ratio now appears consistent with the value previously derived in the Trapezium cluster under similar assumptions of 0.26+/-0.04. We find indications that the relative numbers of brown dwarfs with respect to stars is decreased by a factor 2 in the central regions of the aggregates with respect to the more distributed population. Our findings are best explained in the context of the embryo-ejection model where brown dwarfs originate from dynamical interactions in small N unstable multiple systems.2006A&A...446..485Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/446/485CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/446/485https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/446/485http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/446/485https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/446/485https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/446/485http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/446/485GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/446/485/table3 (Derived parameters and spectral properties of sources identified as field stars or with uncertain membership)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/446/485/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/446/485/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/446/485/table3?GETtext/xml+votable180.050000true60.4892041726.438886940.005555555555555556Cone search capability for table J/A+A/446/485/members (Observed and derived parameters of confirmed Tau cloud members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/446/485/members?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/446/485/members?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/446/485/members?GETtext/xml+votable180.050000true63.8113083328.002670.0055555555555555565/268 6/1030-1031 1037 1039 1046 1048-1050 1052 1054 1060-1061 1069 1076-1078 1080 1082 1159-1160 1168 1170 23549https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/446/485?format=asciiInfrareddefaultJ/A+A/446/485/table3Derived parameters and spectral properties of sources identified as field stars or with uncertain membershiprecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS Namecharn_2MASS[*] *: candidates not selected with the primary selection method (see Sect. 2.1)charRunRun identification numberintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainAVExtinction in V bandmagfloatEWNaEquivalent width of Na line0.1nmfloatEWHaEquivalent width of Halpha line0.1nmfloatSpTypeMK spectral type (Mn.nn)charLClassLuminosity class derived from spectral fittingchar2MASSdataDisplay the 2MASS data for this starcharJ/A+A/446/485/membersObserved and derived parameters of confirmed Tau cloud membersImagI magnitudemagfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS Namecharn_2MASS[*] *: candidates not selected with the primary selection method (see Sect. 2.1)charNameTarget Name (only in table4.dat)charRunRun identification numberintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainAVExtinction in V bandmagfloatEWNaEquivalent width of Na line0.1nmfloatEWHaEquivalent width of Halpha line0.1nmfloatSpTypeMK spectral type (Mn.nn)charLClassLuminosity class derived from spectral fittingchar2MASSdataDisplay the 2MASS data for this starcharlog10(L)logarithm of luminositylog(solLum)floatTeffEffective TemperatureKintI-z? I-z color indexmagfloatnullableJ-HJ-H color indexmagfloatH-KsH-K color indexmagfloatKsmagKs magnitudemagfloat