J/AJ/166/97ivo://CDS.VizieR/J/AJ/166/97doi:10.26093/cds/vizier.51660097CDSLim B.Hong J.Lee J.Yun H.-S.Hwang N.Park B.-G.2025-08-20T20:07:17Z2024-04-05T08:41:50ZCDS support team

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

cds-question@unistra.frstellar-associationsstar-forming-regionsyoung-stellar-objectsvisible-astronomyspectroscopyradial-velocityThe star-forming region W5 is a major part of the Cassiopeia OB6 association. Its internal structure and kinematics may provide hints of the star formation process in this region. Here, we present a kinematic study of young stars in W5 using the Gaia data and our radial velocity data. A total 490 out of 2000 young stars are confirmed as members. Their spatial distribution shows that W5 is highly substructured. We identify a total of eight groups using the k-means clustering algorithm. There are three dense groups in the cavities of H ii bubbles, and the other five sparse groups are distributed at the edges of the bubbles. The three dense groups have almost the same age (5Myr) and show a pattern of expansion. The scale of their expansion is not large enough to account for the overall structure of W5. The three northern groups are, in fact, 3Myr younger than the dense groups, which indicates independent star formation events. Only one of these groups shows the signature of feedback- driven star formation as its members move away from the eastern dense group. The other two groups might have formed in a spontaneous way. On the other hand, the properties of two southern groups are not understood as those of a coeval population. Their origins can be explained by dynamical ejection of stars and multiple star formation. Our results suggest that the substructures in W5 formed through multiple star-forming events in a giant molecular cloud.2023AJ....166...97Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/166/97CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/mk : Catalogue of Stellar Spectral Classifications (Skiff, 2009- )B/simbad : Simbad objects catalogue (M.Wenger 2000)I/337 : Gaia DR1 (Gaia Collaboration, 2016)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)V/125 : Photometry and Spectroscopy for Luminous Stars (Reed 2005)J/AJ/128/805 : Low-mass stars in Cepheus OB2 region (Sicilia-Aguilar+ 2004)J/ApJS/160/319 : COUP; observations and source lists (Getman+, 2005)J/A+A/455/903 : ACIS-I observations of NGC 2264 (Flaccomio+, 2006)J/ApJ/639/1069 : Radial velocities in the CasOB6 association (Hillwig+, 2006)J/A+A/472/835 : JHKs and GLIMPSE photometry of RCW 120 (Zavagno+, 2007)J/ApJ/688/1142 : Star formation in W5; Spitzer observations (Koenig+, 2008)J/MNRAS/415/1202 : BVI photometry in W5E HII region (Chauhan+, 2011)J/ApJ/726/18 : Young intermediate-mass stars in W5 (Koenig+, 2011)J/A+A/539/A74 : NGC1893 Chandra X-ray catalog (Caramazza+, 2012)J/ApJ/787/107 : Spatial structure of young stellar clusters I. (Kuhn+, 2014)J/MNRAS/438/1451 : UBVIH{alpha} photometry of IC 1848 (Lim+, 2014)J/MNRAS/443/454 : UBVIH{alpha} photometry in NGC 1893 (Lim+, 2014)J/MNRAS/477/1993 : NGC 1893 stars LSR velocities (Lim+, 2018)J/ApJS/236/51 : PGCCs in lambda Orionis complex. II. Cores 850um (Yi+, 2018)J/ApJ/870/32 : Kinematics young star clusters & associations (Kuhn+, 2019)J/MNRAS/490/440 : Gaia view of Cygnus OB2 & Carina OB1 assoc (Lim+, 2019)J/ApJS/244/28 : The 3rd MSFRs Omnibus X-ray Catalog (Townsley+, 2019)J/ApJ/899/121 : 127 early type & pre-main-sequence stars in W4 (Lim+, 2020)J/MNRAS/495/663 : Gaia DR2 OB associations (Ward+, 2020)J/AJ/162/56 : Radial velocity of 240 YSO with MMT/Hectochelle (Lim+, 2021)J/ApJS/254/14 : Planck Cold Clumps lambda Orionis complex. III. (Yi+, 2021)J/AJ/163/266 : IGRINS & Gaia; star formation Monoceros OB1 &R1 (Lim+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/166/97https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/166/97http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/166/97https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/166/97https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/166/97http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/166/97GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/166/97/table1 (List of members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/97/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/97/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/97/table1?GETtext/xml+votable180.050000true41.1461160.539713890.005555555555555556Cone search capability for table J/AJ/166/97/table2 (Properties of individual groups)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/97/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/97/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/97/table2?GETtext/xml+votable180.050000true41.9961330660.703093890.0055555555555555565/825 6/3278-3279 3290 3297 3312 33141.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/166/97?format=asciiOpticaldefaultJ/AJ/166/97/table1List of membersSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/490] Sequential identifiermeta.id;meta.mainintRAJ2000[41/46] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[59/62] Declination (J2000)degpos.eq.dec;meta.mainplx[0.28/0.99] Gaia EDR3 parallaxmaspos.parallax.trigfloate_plx[0.01/0.4] Uncertainty in plxmasstat.error;pos.parallaxfloatpmRA[-2.1/1.45] Gaia EDR3 proper motion in RAmas/yrpos.pm;pos.eq.rafloate_pmRA[0.01/0.3] Uncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-2.13/1.44]? Gaia EDR3 proper motion in DEmas/yrpos.pm;pos.eq.decfloatnullablee_pmDE[0.01/0.4] Uncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatRVel[-54.1/-5.06]? Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatnullableGroupGroup (Table 2)meta.idcharRV-LSR[-51.1/-1.99]? Radial velocity in the local standard of rest framekm/sspect.dopplerVeloc;pos.lsrfloatnullablee_RVel[0.2/5]? Uncertainty in Radial Velocitykm/sstat.error;spect.dopplerVelocfloatnullableGmag[7.81/19.2] Gaia EDR3 G-band magnitudemagphot.mag;em.opt.VfloatBPmag[7.99/20.9] Gaia EDR3 BP-band magnitudemagphot.mag;em.opt.BfloatRPmag[7.46/18] Gaia EDR3 RP-band magnitudemagphot.mag;em.opt.RfloatBP-RP[0.48/4.32] Gaia EDR3 BP-RP colormagphot.color;em.opt.B;em.opt.RfloatRemarkRemarks (1)meta.notecharJ/AJ/166/97/table2Properties of individual groupsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGroupGroupmeta.id;meta.maincharprimaryRAJ2000[41/46] Median group Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[59/61] Median group Declination (J2000)degpos.eq.dec;meta.mainpmRA[-0.62/0.21] Median group proper motion in RAmas/yrpos.pm;pos.eq.rafloatpmDE[-0.64/-0.03] Median group proper motion in DEmas/yrpos.pm;pos.eq.decfloatVT-RA[-6.1/2] Median tangential velocity in RAkm/sphys.veloc.transversefloatVT-DE[-6.3/-0.4] Median tangential velocity in DEkm/sphys.veloc.transversefloatRV-LSR[-39.2/-29.1]? Median Radial velocity in the local standard of rest framekm/sspect.dopplerVeloc;stat.medianfloatnullablesigVT-RA[2.4/6.9] Dispersion of tangential velocity along RAkm/sphys.veloc.dispersionfloatsigVT-DE[2/8.7] Dispersion of tangential velocity along DEkm/sphys.veloc.dispersionfloatsigRV-LSR[0.6/3.5]? Dispersion of RV-LSRkm/sphys.veloc.dispersionfloatnullableNgrp[10/159] number of group membersmeta.numberintNrv[0/25] number of group members with RVmeta.numberintMST[0.62/1.73] minimum spanning treemeta.notefloat