J/ApJ/602/816ivo://CDS.VizieR/J/ApJ/602/816doi:10.26093/cds/vizier.16020816CDSLuhman K.L.2021-08-04T07:05:25Z2014-02-13T09:03:06ZCDS support team

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

cds-question@unistra.frstellar-associationspre-main-sequence-starsinfrared-photometryI present a new census of the members of the Chamaeleon I star-forming region. Optical spectroscopy has been obtained for 179 objects that have been previously identified as possible members of the cluster, that lack either accurate spectral types or clear evidence of membership, and that are optically visible (I<~18). I have used these spectroscopic data and all other available constraints to evaluate the spectral classifications and membership status of a total sample of 288 candidate members of Chamaeleon I that have appeared in published studies of the cluster. The latest census of Chamaeleon I now contains 158 members, eight of which are later than M6 and thus are likely to be brown dwarfs. I find that many of the objects identified as members of Chamaeleon I in recent surveys are actually field stars. Meanwhile, seven of nine candidates discovered by Carpenter and coworkers are confirmed as members, one of which is the coolest known member of Chamaeleon I at a spectral type of M8 (~0.03M_{sun}_). I have estimated extinctions, luminosities, and effective temperatures for the members and used these data to construct an H-R diagram for the cluster. Chamaeleon I has a median age of ~2Myr according to evolutionary models and hence is similar in age to IC 348 and is slightly older than Taurus (~1Myr). The measurement of an initial mass function for Chamaeleon I from this census is not possible because of the disparate methods with which the known members were originally selected and must await an unbiased, magnitude-limited survey of the cluster.2004ApJ...602..816Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/602/816CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/267/755 : Polarimetry in the Chamaeleon I Dark Cloud (McGregor+, 1994)J/A+A/357/219 : ISOCAM observations in Cha I. (Persi+, 2000)J/AJ/121/974 : JHK photometry in Cha I (Gomez+, 2001)J/AJ/121/2673 : 3{mu}m survey of the Chamaeleon I dark cloud (Kenyon+, 2001)J/A+A/423/1029 : XMM-Newton obs, in Cha I South (Stelzer+, 2004)J/AJ/124/1001 : JHKs photometry of Cha I variables (Carpenter, 2002)J/ApJ/614/267 : Chandra sources in Cha I North (Feigelson+, 2004)J/ApJS/173/104 : Stellar population in Chamaeleon I (Luhman, 2007)J/A+A/461/669 : XMM observations of Cha I dark cloud (Robrade+, 2007)J/ApJ/675/1375 : IRAC/MIPS photometry in Cha I (Luhman+, 2008)J/ApJ/684/654 : Low-mass members of Chamaeleon I (Luhman+, 2008)J/A+A/527/A145 : Chamaeleon I 870um sources (Belloche+, 2011)J/A+A/551/A46 : Cha I & II members compiled photometry (Lopez Marti+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/602/816https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/602/816http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/602/816https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/602/816https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/602/816http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/602/816GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/602/816/members (Astrometry and photometry (table4) and derived properties (table5) for members of Chamaeleon I)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/602/816/members?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/602/816/members?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/602/816/members?GETtext/xml+votable180.050000true161.658125-77.6010.005555555555555556Cone search capability for table J/ApJ/602/816/non_memb (Non-member stars: foreground (table6) or background (table7))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/602/816/non_memb?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/602/816/non_memb?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/602/816/non_memb?GETtext/xml+votable180.050000true165.3335-77.60350.005555555555555556Cone search capability for table J/ApJ/602/816/table8 (Sources with uncertain membership status)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/602/816/table8?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/602/816/table8?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/602/816/table8?GETtext/xml+votable180.050000true165.6948333-77.63555560.0055555555555555565/9239 6/36951 36952 36953 36955 37122 371281.3891223550672228e-20 2.689546822829005e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/602/816?format=asciiInfrareddefaultJ/ApJ/602/816/table2H{alpha} for members of Chamaeleon IrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource namemeta.id;meta.maincharl_EWLimit flag on EWmeta.code.error;spect.line.eqWidthcharEWEquivalent width of the H{alpha} line0.1nmspect.line.eqWidthfloate_EW? rms uncertainty on EW0.1nmstat.error;spect.line.eqWidthfloatnullablel_FluxLimit flag on Fluxmeta.code.error;phot.fluxcharFlux? Observed H{alpha} line flux (10^-15^erg/cm^2^/s)aW.m**-2phot.flux;em.line.Halphafloatnullablel_log(LHa/Lb)Limit flag on log(LHa/Lb)meta.code.errorcharlog(LHa/Lb)? H{alpha} to bolometric luminosity ratio (typical error is +/-0.1)phys.luminosity;arith.ratiofloatnullableSpTSpectral typesrc.spTypecharJ/ApJ/602/816/membersAstrometry and photometry (table4) and derived properties (table5) for members of Chamaeleon ISimbadNameSimbad column added by the CDSmeta.idcharImag? DENIS second release (II/252) I magnitudemagphot.mag;em.opt.IfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource namemeta.id;meta.maincharprimaryn_ID[ef ] Note(s) on source (1)meta.notecharWmeta.ref.urlcharRAJ2000Right ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (2)pos.eq.dec;meta.mainJ-H? 2MASS J-H colour index (3)magphot.color;em.IR.J;em.IR.HfloatnullableH-Ks? 2MASS H-Ks colour indexmagphot.color;em.IR.H;em.IR.KfloatnullableKsmag? 2MASS Ks magnitudemagphot.mag;em.IR.Kfloatnullable[6.7]? Magnitude at 6.7um (4)magphot.flux.density;em.IR.4-8umfloatnullablee_[6.7]? rms uncertainty on [6.7]magstat.errorfloatnullable[14.3]? Magnitude at 14.3um (4)magphot.flux.density;em.IR.8-15umfloatnullablee_[14.3]? rms uncertainty on [14.3]magstat.errorfloatnullableSpT/W(Ha)Spectral type /EW(H{alpha}) value(s) (1)src.spTypecharr_SpT/W(Ha)Reference(s) for SpT/W(Ha), in refs.dat filemeta.ref;pos.framecharSpTAdopted spectral typesrc.spTypecharMembMembership evidences (G1)meta.code.memberr_MembReference(s) for Membership evidence, in refs.dat filemeta.ref;pos.framecharTeff? Effective temperature (3)Kphys.temperature.effectiveintnullableAJ? Absorption in J bandmagphot.magfloatnullableLbol? Bolometric luminositysolLumphys.luminositydoublenullableJ/ApJ/602/816/table3Li{lambda}6707 for members of Chamaeleon IrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource namemeta.id;meta.maincharEWEquivalent width of the Li{lambda}6707 line0.1nmspect.line.eqWidthfloate_EWrms uncertainty on EW0.1nmstat.error;spect.line.eqWidthfloatSpTSpectral typesrc.spTypecharJ/ApJ/602/816/non_membNon-member stars: foreground (table6) or background (table7)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStmeta.code.membercharIDSource namemeta.id;meta.maincharn_ID[d] d indicates additional comments on this source in the Appendixmeta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainSpTSpectral type(s)src.spTypecharr_SpTReferences for SpT, in refs.dat filemeta.ref;pos.framecharEvidForeground or Background evidence (G1)meta.codecharr_EvidReference for evidence, in refs.dat filemeta.ref;pos.framecharImag? I magnitude from Second DENIS Releasemagphot.mag;em.opt.IfloatnullableJ-H2MASS PSC J-H colour indexmagphot.color;em.IR.J;em.IR.HfloatH-Ks2MASS PSC H-Ks colour indexmagphot.color;em.IR.H;em.IR.KfloatKsmag2MASS PSC Ks magnitudemagphot.mag;em.IR.KfloatJ/ApJ/602/816/table8Sources with uncertain membership statusSimbadNameSimbad column added by the CDSmeta.idcharr_SpTReferences for SpT (1)meta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource namemeta.id;meta.maincharn_ID[c] indicates additional comments on this source in the Appendixmeta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainr[1/2] Reference for position (1)meta.ref;pos.frameintSpTSpectral type(s)src.spTypecharStatusStatus (Background?, Member?, or ?)meta.code.membercharImag? I magnitude from Second DENIS Releasemagphot.mag;em.opt.IfloatnullableJ-H? 2MASS PSC J-H colour indexmagphot.color;em.IR.J;em.IR.HfloatnullableH-Ks? 2MASS PSC H-Ks colour indexmagphot.color;em.IR.H;em.IR.KfloatnullableKsmag? 2MASS PSC Ks magnitudemagphot.mag;em.IR.KfloatnullableJ/ApJ/602/816/refsReferencesComCommentsmeta.notecharAutAuthor's namemeta.bib.authorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference numbermeta.id;meta.mainintBibCodeBibCodemeta.bib.bibcodechar