J/A+A/567/A52ivo://CDS.VizieR/J/A+A/567/A52doi:10.26093/cds/vizier.35670052CDSKlutsch A.Freire Ferrero R.Guillout P.Frasca A.Marilli E.,Montes D.2017-09-27T05:56:01Z2014-10-20T10:34:25ZCDS support team

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

cds-question@unistra.frstellar-associationsOver the last century, the overdensities in the velocity distributions of nearby stars were attributed to stellar kinematic groups or moving groups. Although their reality was initially questioned, their existence is now supported by a confluence of evidence. To pursue investigations, quantitative methods should be clearly defined to identify new stars belonging to these groups. Here, we present two probabilistic methods to determine the likelihood of kinematic membership for possible candidates in five of the known young stellar kinematic groups - namely, Pleiades, IC2391, Castor, Ursa Major, and Hyades - in which all are younger than 650Myr. We tried different methods to handle kinematic data of their known members. We succeeded in developing two independent procedures able to identify new candidates of these five stellar stream. We tested the robustness of our two approaches by means of extensive Monte Carlo simulations. Our methods are consistent with one another in more than 90% of cases and for almost all the stellar kinematic groups under scrutiny. The IC2391 supercluster is an exception. Applying our statistical methods to a large sample of young low-mass stars, we confirmed almost all the likely members and good candidates of these stellar streams. We also proposed 39 additional candidates based on the agreement and the high likelihood of age and kinematic membership. These probabilistic methods are very powerful to reliably identify new candidate members of young stellar kinematic groups. However, the kinematic criteria alone are not sufficient to distinguish between coeval stars that are evaporated from open clusters and other field stars trapped by dynamical processes generated by galactic perturbations. The identification of stars belonging to the remnant of a past star-forming event can be possible with the help of additional information, such as indicators of chromospheric activity, age proxies (lithium abundance), and chemical composition.2014A&A...567A..52Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/567/A52CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/567/A52https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/567/A52http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/567/A52https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/567/A52https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/567/A52http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/567/A52GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/567/A52/table4 (Kinematic properties of young low-mass stars and their likelihood of membership in stellar kinematic groups (SKG))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/567/A52/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/567/A52/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/567/A52/table4?GETtext/xml+votable180.050000true0.9261667-28.37805560.0055555555555555566/134 265 472 483 518 636 728 847 989 1122 1138 1453 1819 1911 2425 2516 2534 2545 2660 2783 2800 2809 2844 3045 3050 3293 3347 3591 4401 4444 4468 4685 4739 4764 5387 5420 5429 5504 5659 5743 5819 5854 5998 6169 6384 6879 7147 7810 8627 8684 8690 9311 9429 9747 10381 10771 10905 11208 11480 13158 13355 13427 13670 13732 13736 13743 14450 14580 15355 15686 15896 16097 16577 16827 17155 17606-17607 17890 18503 18538 18743 19163 19879 19957 20084 20163 20240 20257 20282 20381 20425 20472-20473 20505 21180 21420 22215 22390 22603 22683 22739 22773 22904 23094 23111 23510 23752 23895 24103 25637 26555 27438 27537 27611 27792 28087 28162 28195 29744 32089 32158 32500 32541 34680 35640 36528 39829 40748 43838 44194 44386 45035 46922 48124 48361 48801 49029 49146-49147https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/567/A52?format=asciiOpticaldefaultJ/A+A/567/A52/table4Kinematic properties of young low-mass stars and their likelihood of membership in stellar kinematic groups (SKG)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharn_Name[c] Young star without association (1)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainUvelU space velocitykm/sphys.veloc;pos.cartesian.xfloatVvelV space velocitykm/sphys.veloc;pos.cartesian.yfloatWvelW space velocitykm/sphys.veloc;pos.cartesian.zfloatPS12? Probability of kinematic match from S12 (Shkolnik et al., 2012ApJ...758...56S, Cat. J/ApJ/758/56)%statintnullableP2D[0/99]? Probability of 2D kinematic match%statintnullableP3D[0/99]? Probability of 3D kinematic match%statfloatnullableS12Best kinematic group match from S12 criteriameta.id.parentcharo_S12Number of sources classified in this group from S12meta.numberintnullableM2MBest kinematic group match from M2M method (2)meta.id.parentcharCESBest kinematic group match from CES method (2)meta.id.parentcharEggBest kinematic group match from Eggen's criteriameta.id.parentcharQ1[AB-] Match 3-criteria quality from S12 (A=best)meta.code.qualcharQ2Match quality from our index (3)meta.code.qualcharl_Age[~ =>] Limit flag on Agemeta.code.error;time.ageAge? Stellar age or lower value if interval from Shkolnik et al. (2009ApJ...699..649S, Cat. J/ApJ/699/649)Myrtime.ageintnullableAge2? Upper value of stellar age if intervalMyrtime.age;stat.maxintnullableSKGLikely SKG members/candidates (4)meta.id.parentcharNsNumber of sources classified in this groupmeta.numberintnullable