J/AJ/156/271ivo://CDS.VizieR/J/AJ/156/271doi:10.26093/cds/vizier.51560271CDSLuhman K.L.2020-03-31T12:49:36Z2019-04-26T07:26:12ZCDS support team

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

cds-question@unistra.frstar-forming-regionsstellar-populationsstellar-spectral-typesproper-motionsvisible-astronomytrigonometric-parallaxradial-velocityphotometryinfrared-photometryThe high-precision astrometry from the second data release of the Gaia mission (Cat. I/345) has made it possible to greatly improve the census of members of nearby clusters and associations. I have applied the Gaia data to the Taurus star-forming region, refining the sample of known members and identifying candidates for undiscovered members. The resulting samples of members and candidates provide the best constraints to date on the distribution of ages and the initial mass function (IMF) in Taurus. Several studies over the last 30 years have proposed the existence of a population of older stars (>~10 Myr) that is associated with the Taurus clouds. The data from Gaia demonstrate that such a population does not exist. Meanwhile, previous IMF estimates for small fields surrounding the Taurus aggregates have exhibited a surplus of K7-M0 stars (0.7-0.8 M_{sun}_) relative to star-forming clusters such as IC 348 and the Orion Nebula Cluster. However, that difference disappears when the new census of the entire region is considered, which should be complete for spectral types earlier than M6-M7 at A_J_<1. Thus, there is little variation in the stellar IMF across the 3-4 orders of magnitude in stellar density that are present in nearby star-forming regions. Finally, I note that the proper motions of two previously known members, KPNO 15 and 2MASS J04355209+2255039, indicate that they may have been ejected from the same location within the L1536 cloud ~7200 years ago.2018AJ....156..271Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/156/271CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)III/252 : Pulkovo radial velocities for 35493 HIP stars (Gontcharov, 2006)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/312/439 : New T Tauri stars in Taurus-Auriga (Wichmann+, 1996)J/ApJS/155/175 : MK Classification of Bright Star Supplement (Abt, 2004)J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)J/ApJS/186/111 : Spitzer observations of Taurus members (Luhman+, 2010)J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)J/ApJ/745/119 : Close companions to young stars. I. ChaI + Tau (Nguyen+, 2012)J/ApJ/784/126 : Infrared photometry of all known members in TaurusJ/ApJ/786/97 : Photospheric properties of T Tauri stars (Herczeg+, 2014)J/AJ/153/46 : Spectroscopy of candidate members in Taurus (Luhman+, 2017)J/AJ/153/257 : Comoving stars in Gaia DR1 (Oh+, 2017)J/AJ/154/134 : Planetary-mass brown dwarfs in the Taurus SFR (Esplin+, 2017)J/ApJ/838/150 : The Taurus-Auriga ecosystem. I. (Kraus+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/156/271https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/156/271http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/156/271https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/156/271https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/156/271http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/156/271GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/156/271/table1 (Members of Taurus)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/271/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/271/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/271/table1?GETtext/xml+votable180.050000true60.9583226.343863890.005555555555555556Cone search capability for table J/AJ/156/271/Candidates (Candidate members of group 29 (as defined in Oh et al. 2017AJ....153..257O) and of Taurus (tables 5 et 6 respectively))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/271/Candidates?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/271/Candidates?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/271/Candidates?GETtext/xml+votable180.050000true60.1694111120.413271940.0055555555555555565/86 92 259 262 268 269 270 278 289 292 5886 5887 6056 6/324 327 329 331 335 336 337 338 342 343 350 359 377 380 1027 1029 1030 1031 1033 1034 1040 1042 1043 1046 1047 1052 1053 1054 1061 1062 1063 1066 1068 1069 1084 1086 1098 1102 1104 1106 1107 1108 1110 1111 1119 1121 1123 1124 1125 1126 1133 1136 1152 1154 1161 1165 1167 1174 1176 23517 23518 23519 23527 23533 23538 23542 23543 24107 24120 24194 24195 24196 24197 24199 24201 24202 24203 24205 24207 24209 24215 24218 24219 24220 24232 24233 24238 24239 24245 24249 24250 24251 24270 24289 24294 24295 24297 243008.650015785639275e-20 4.621782916333392e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/156/271?format=asciiOpticalInfrareddefaultJ/AJ/156/271/table1Members of TaurusSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS? 2MASS Point Source Catalog source name (JHHMMSSss+DDMMSSs)meta.id;meta.maincharUGCS? UKIDSS Galactic Clusters Survey source name (1)meta.idcharOName? Other source namemeta.idcharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainrPosReference for Right Ascension and Declination (2)meta.ref;pos.framecharSpType? Adopted spectral type (3)src.spTypecharpmRA[-1.889/28.987]? Gaia DR2 proper motion in right ascension (pmRA*cosDE)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA[0.067/4.285]? Error in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE[-30.258/-8.093]? Gaia DR2 proper motion in declinationmas/yrpos.pm;pos.eq.decfloatnullablee_pmDE[0.04/3.452]? Error in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatnullableplx[2.257/11.856]? Gaia DR2 parallaxmaspos.parallax.trigfloatnullablee_plx[0.035/2.407]? Error in plxmasstat.error;pos.parallaxfloatnullableRV[8.9/22.45]? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV[0.01/3.1]? Error in RVelkm/sstat.errorfloatnullabler_RV[1/13]? Radial velocity reference (4)meta.ref;pos.frameintnullableU[-20.34/-9.64]? U component of space velocitykm/sphys.veloc;pos.cartesian.xfloatnullablee_U[0.04/3.02]? Error in Ukm/sstat.error;pos.cartesian.xfloatnullableV[-16.85/-8.6]? V component of space velocitykm/sphys.veloc;pos.cartesian.yfloatnullablee_V[0.07/2.44]? Error in Vkm/sstat.error;pos.cartesian.yfloatnullableW[-12.86/-2.56]? W component of space velocitykm/sphys.veloc;pos.cartesian.zfloatnullablee_W[0.03/1.68]? Error in Wkm/sstat.error;pos.cartesian.zfloatnullableGmag[6.518/21.165]? Gaia DR2 G magnitudemagphot.mag;em.optfloatnullablee_Gmag[0.001/0.065]? Error in Gmagmagstat.error;phot.mag;em.opt.BfloatnullableGBPmag[6.532/22.284]? Gaia DR2 G_BP_ magnitudemagphot.mag;em.opt.Bfloatnullablee_GBPmag[0.001/0.731]? Error in GBPmagmagstat.error;phot.magfloatnullableGRPmag[6.529/19.212]? Gaia DR2 G_RP_ magnitudemagphot.mag;em.opt.Rfloatnullablee_GRPmag[0.001/0.197]? Error in GRPmagmagstat.error;phot.magfloatnullablePop? Color code for the kinematic populations in Figures 2-11 of this papermeta.codecharJ/AJ/156/271/CandidatesCandidate members of group 29 (as defined in Oh et al. 2017AJ....153..257O) and of Taurus (tables 5 et 6 respectively)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion namemeta.id.parentchar2MASS? 2MASS Point Source Catalog source name (JHHMMSSss+DDMMSSs)meta.id;meta.maincharOName? Other source name (only in Table 5)meta.idcharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainpmRA[-5.79/14.318] Gaia DR2 proper motion in right ascension (pmRA*cosDE)mas/yrpos.pm;pos.eq.rafloate_pmRA[0.06/0.663] Error in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-27.385/-12.524] Gaia DR2 proper motion in declinationmas/yrpos.pm;pos.eq.decfloate_pmDE[0.034/0.474] Error in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplx[4.906/8.595] Gaia DR2 parallaxmaspos.parallax.trigfloate_plx[0.036/0.43] Error in plxmasstat.error;pos.parallaxfloatGmag[7.136/18.553] Gaia DR2 G magnitudemagphot.mag;em.optfloate_Gmag[0.001/0.006] Error in Gmagmagstat.error;phot.mag;em.opt.BfloatGBPmag[7.179/20.836]? Gaia DR2 G_BP_ magnitudemagphot.mag;em.opt.Bfloatnullablee_GBPmag[0.001/0.198]? Error in GBPmagmagstat.error;phot.magfloatnullableGRPmag[7.103/17.007]? Gaia DR2 G_RP_ magnitudemagphot.mag;em.opt.Rfloatnullablee_GRPmag[0.001/0.02]? Error in GRPmagmagstat.error;phot.magfloatnullableJmag[7/14.56]? 2MASS J magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag[0.02/0.04]? Error in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag[7.03/13.96]? 2MASS H magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0.01/0.05]? Error in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKsmag[7.02/13.56]? 2MASS K_s_ magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag[0.01/0.05]? Error in Ksmagmagstat.error;phot.mag;em.IR.Kfloatnullable