J/ApJ/867/151ivo://CDS.VizieR/J/ApJ/867/151doi:10.26093/cds/vizier.18670151CDSDzib S.A.Loinard L.Ortiz-Leon G.N.Rodriguez L.F.Galli P.A.B.2020-10-19T08:24:58Z2019-11-18T14:16:30ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsstar-forming-regionsvisible-astronomytrigonometric-parallaxproper-motionsastrometryWe present an analysis of the astrometric results from the Gaia second data release (DR2) for young stellar objects (YSOs) in star-forming regions related to the Gould Belt (GB). These regions are Barnard 59, Lupus 1 to 4, Chamaeleon I and II, {epsilon} Chamaeleontis, the Cepheus flare, IC 5146, and Corona Australis. The mean distance to the YSOs in each region is consistent with earlier estimations, though a significant improvement in the final errors was obtained. The mean distances to the star-forming regions were used to fit an ellipsoid of size (358+/-7)x(316+/-13)x(70+/-4)pc^3^, centered at (X0,Y0,Z0)=(-82+/-15,39+/-7,-25+/-4)pc, consistent with recently determined parameters of the GB. The mean proper motions were combined with radial velocities from the literature to obtain the three- dimensional motions of the star-forming regions, which are consistent with a general expansion of the GB. We estimate that this expansion is occurring at a velocity of 2.5+/-0.1km/s. This is the first time that motions of YSOs have been used to investigate the kinematics of the GB. As an interesting side result, we also identified stars with large peculiar velocities.2018ApJ...867..151Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/867/151CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+AS/146/323 : RASS young sources around R CrA (Neuhaeuser+, 2000)J/ApJ/680/495 : Interstellar clouds survey in the Gould belt (Harvey+, 2008)J/ApJ/702/178 : YSOs in the central 400pc of the Galaxy (Yusef-Zadeh+, 2009)J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)J/ApJS/194/43 : YSOs candidates and knots in CrA cloud (Peterson+, 2011)J/PAZh/39/601 : Galactic kinematics from YSOs sample (Bobylev+, 2013)J/MNRAS/438/1848 : NGC 7129 Vilnius photometry (Straizys+, 2014)J/A+A/584/A26 : Cosmography of OB stars in solar neighbourhood (Bouy+, 2015)J/ApJ/806/231 : MISFITS survey: HCO+ obs. of Spitzer YSOs (Heiderman+, 2015)J/ApJS/220/11 : SEDs of Spitzer YSOs in the Gould Belt (Dunham+, 2015)J/ApJ/834/142 : Gould's Belt Distances Survey. II. (Kounkel+,2017)J/ApJ/859/33 : GOBELINS. IV. VLBA obs. of Taurus (Galli+, 2018)J/A+A/610/A64 : Distance to the clouds in Chamaeleon complex (Voirin+, 2018)J/A+A/619/A106 : 3D shape of Orion A from Gaia DR2 (Grossschedl+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/867/151https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/867/151http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/867/151https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/867/151https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/867/151http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/867/151GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/867/151/table1 (Astrometric parameters of YSOs used in our analysis from the Gaia-DR2 catalog (I/345))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/867/151/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/867/151/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/867/151/table1?GETtext/xml+votable180.050000true257.8220029-27.41901940.005555555555555556Cone search capability for table J/ApJ/867/151/table4 (Distances, mean proper motions, and mean radial velocities of star-forming regions in the Gould Belt)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/867/151/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/867/151/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/867/151/table4?GETtext/xml+votable180.050000true257.825-27.36670.0055555555555555565/10283 6/862 1168 1539 14029 14031 14040 14042 14053 15759 15781 15791 15797 15798 15830 15840 15843 15855 15965 16129 16131 16133 16185 16188 16189 16191 16197 16208 16226 16320 21438 29193 36946 36948 36955 36956 36957 36958 37120 37125 37128 37137 41122 41123 41127 41128 41130 41472 41474 41484 41505 41600 41635 42595 42596 42597 42598 42611 42614 42615 42617 42619 42704 42707 42714 42727 42736 42737 42738 42981 47739 47741 47742 47825 47828https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/867/151?format=asciiOpticaldefaultJ/ApJ/867/151/table1Astrometric parameters of YSOs used in our analysis from the Gaia-DR2 catalog (I/345)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameYSO namemeta.id;meta.maincharGaiaGaia DR2 source identification numbermeta.idRA_ICRS[163.4/342.4] Right ascension, decimal degrees (ICRS) at Ep=2015.5 (1)degpos.eq.ra;meta.mainDE_ICRS[-79.9/78.4] Declination, decimal degrees (ICRS) at Ep=2015.5 (1)degpos.eq.dec;meta.mainplx[0.6/11] Gaia DR2 parallax (1)maspos.parallax.trigfloate_plx[0.01/1.2] Mean error on parallax (1)masstat.error;pos.parallaxfloatpmRA[-45.2/18] Proper motion in right ascension (1)mas/yrpos.pm;pos.eq.rafloate_pmRA[0.01/2.4] Mean error on proper motion in right ascension (1)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-32.1/7] Proper motion in declination (1)mas/yrpos.pm;pos.eq.decfloate_pmDE[0.01/1.8] Mean error on proper motion in declination (1)mas/yrstat.error;pos.pm;pos.eq.decfloatRegStar forming regionmeta.id.parentcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decnullableindexedJ/ApJ/867/151/table4Distances, mean proper motions, and mean radial velocities of star-forming regions in the Gould BeltSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegStar forming regionmeta.idcharDist[129.5/388] Distancepcpos.distance;pos.heliocentricfloate_Dist[0.3/32] Dist uncertaintypcstat.errorfloatpmRA[-22.8/8.56] Proper motion along RAmas/yrpos.pm;pos.eq.rafloate_pmRA[0.02/0.2] pmRA uncertaintymas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-27.3/0.4] Proper motion along DECmas/yrpos.pm;pos.eq.decfloate_pmDE[0.01/0.5] pmDE uncertaintymas/yrstat.error;pos.pm;pos.eq.decfloatRV[-1/27] Radial velocitykm/sphys.veloc;pos.heliocentricfloate_RV[0.1/4]? RV uncertaintykm/sstat.errorfloatnullableRefReference(s) (1)meta.ref;pos.framecharNysoNumber of YSOs for this region (link to Table 1)meta.numberintnullable_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