J/A+A/601/A97ivo://CDS.VizieR/J/A+A/601/A97doi:10.26093/cds/vizier.36010097CDSSacco G.G.Spina L.Randich S.Palla F.Parker R.J.Jeffries R. D.,Jackson R.Meyer M.R.Mapelli M.,Lanzafame A.C.Bonito R.Damiani F.,Franciosini E.Frasca A.Klutsch A.Prisinzano L.Tognelli E.,Degl'Innocenti S.Prada Moroni P.G.Alfaro E.J.Micela G.Prusti T.,Barrado D.Biazzo K.Bouy H.Bravi L.Lopez-Santiago J.Wright N.J.,Bayo A.Gilmore G.Bragaglia A.Flaccomio E.Koposov S.E.Pancino E.,Casey A.R. Costado M.T.Donati P.Hourihane A.Jofre P.Lardo C.,Lewis J.Magrini L.Monaco L.Morbidelli L.Sousa S.G.Worley C.C.,Zaggia S.2017-05-12T15:35:18Z2017-05-10T08:47:16ZCDS support team

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

cds-question@unistra.fropen-star-clustersradial-velocityeffective-temperaturestellar-massesInvestigating the physical mechanisms driving the dynamical evolution of young star clusters is fundamental to our understanding of the star formation process and the properties of the Galactic field stars. The young (~2Myr) and partially embedded cluster Chamaeleon I is one of the closest laboratories to study the early stages of star cluster dynamics in a low-density environment. The aim of this work is to study the structural and kinematical properties of this cluster combining parameters from the high-resolution spectroscopic observations of the Gaia-ESO Survey with data from the literature. Our main result is the evidence of a large discrepancy between the velocity dispersion ({sigma}_stars_=1.14+/-0.35km/s) of the stellar population and the dispersion of the pre-stellar cores (~0.3km/s) derived from submillimeter observations. The origin of this discrepancy, which has been observed in other young star clusters is not clear. It has been suggested that it may be due to either the effect of the magnetic field on the protostars and the filaments, or to the dynamical evolution of stars driven by two-body interactions. Furthermore, the analysis of the kinematic properties of the stellar population put in evidence a significant velocity shift (~1~km/s) between the two sub-clusters located around the North and South main clouds of the cluster. This result further supports a scenario, where clusters form from the evolution of multiple substructures rather than from a monolithic collapse.Using three independent spectroscopic indicators (the gravity indicator {gamma}, the equivalent width of the Li line at 6708{AA}, and the H{alpha} 10% width), we performed a new membership selection. We found six new cluster members all located in the outer region of the cluster, proving that Chamaeleon I is probably more extended than previously thought. Starting from the positions and masses of the cluster members, we derived the level of substructure Q, the surface density {Sigma} and the level of mass segregation {Lambda}_MSR_ of the cluster. The comparison between these structural properties and the results of N-body simulations suggests that the cluster formed in a low density environment, in virial equilibrium or supervirial, and highly substructured.2017A&A...601A..97Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/601/A97CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/575/A4 : Activity and accretion in {gamma} Vel and Cha I (Frasca+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/601/A97https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/601/A97http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/601/A97https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/601/A97https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/601/A97http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/601/A97GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/601/A97/table1 (Members of Cha I observed by the Gaia-ESO Survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/601/A97/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/601/A97/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/601/A97/table1?GETtext/xml+votable180.050000true163.79017-77.5150.005555555555555556Cone search capability for table J/A+A/601/A97/table2 (Members of Cha I used for the structural analysis)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/601/A97/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/601/A97/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/601/A97/table2?GETtext/xml+votable180.050000true161.65812-77.600970.0055555555555555565/9239 9282 6/36946 36949 36953 36955 37122-37123 37127https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/601/A97?format=asciiOpticaldefaultJ/A+A/601/A97/table1Members of Cha I observed by the Gaia-ESO SurveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCommon name of Gaia-ESO targets, HHMMSSss+DDMMSSsmeta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainHRV? Heliocentric radial velocity (1)km/sspect.dopplerVeloc;pos.heliocentricfloatnullablee_HRV? Error on heliocentric velocity (1)km/sstat.errorfloatnullableTeff? Effective temperatureKphys.temperature.effectiveintnullablee_Teff? Error on effective temperatureKstat.error;phys.temperature.effectiveintnullableGamma? Empirical gravity index (2)spect.indexfloatnullablee_Gamma? Error on empirical gravity index (2)stat.errorfloatnullableEW(Li)? Equivalent width of the Li line at 607.8nm0.1pmspect.line.eqWidth;em.opt.Rintnullablee_EW(Li)? Error on EW(Li)0.1pmstat.errorintnullableHa10? Width of the Halpha at 10% of the peakkm/sspect.line.eqWidthintnullablee_Ha10? Error on Ha10km/sstat.errorintnullableSpecSpectrograph used for the observation (3)meta.id;instrcharMemb[YNS ] Membership flag (4)meta.code.errorcharAllDisplay data for this star in all tablesmeta.ref.urlcharJ/A+A/601/A97/table2Members of Cha I used for the structural analysislogLbolBolometric luminosity (1)log(solLum)phys.luminosityfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainTeffEffective temperatureKphys.temperature.effectiveintProv[GL] Origin of the parameters (2)meta.bibcharMass? Stellar masssolMassphys.massfloatnullableAllDisplay data for this star in all tablesmeta.ref.urlchar