J/MNRAS/459/610ivo://CDS.VizieR/J/MNRAS/459/610doi:10.26093/cds/vizier.74590610CDSMarino A.F.Milone A.P.Casagrande L.Collet R.Dotter A.,Johnson C.I.Lind K.Bedin L.R.Jerjen H.Aparicio A.Sbordone L.2024-08-16T20:17:04Z2017-08-01T08:12:30ZCDS support team

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

cds-question@unistra.frglobular-star-clustersvisible-astronomybroad-band-photometrychemical-abundancesThe globular cluster 47 Tuc exhibits a complex sub-giant branch (SGB) with a faint-SGB comprising only about the 10 per cent of the cluster mass and a bright-SGB hosting at least two distinct populations. We present a spectroscopic analysis of 62 SGB stars including 21 faint-SGB stars. We thus provide the first chemical analysis of the intriguing faint-SGB population and compare its abundances with those of the dominant populations. We have inferred abundances of Fe, representative light elements C, N, Na, and Al, {alpha} elements Mg and Si for individual stars. Oxygen has been obtained by co-adding spectra of stars on different sequences. In addition, we have analysed 12 stars along the two main RGBs of 47 Tuc. Our principal results are (i) star-to-star variations in C/N/Na among RGB and bright-SGB stars; (ii) substantial N and Na enhancements for the minor population corresponding to the faint-SGB; (iii) no high enrichment in C+N+O for faint-SGB stars. Specifically, the C+N+O of the faint-SGB is a factor of 1.1 higher than the bright-SGB, which, considering random (+/-1.3) plus systematic errors (+/-0.3), means that their C+N+O is consistent within observational uncertainties. However, a small C+N+O enrichment for the faint-SGB, similar to what predicted on theoretical ground, cannot be excluded. The N and Na enrichment of the faint-SGB qualitatively agrees with this population possibly being He-enhanced, as suggested by theory. The iron abundance of the bright and faint-SGB is the same to a level of ~0.10dex, and no other significant difference for the analysed elements has been detected.2016MNRAS.459..610Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/459/610CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/85/293 : HST Observations of core of 47 Tuc (de Marchi+ 1993)J/A+A/372/85 : Detected sources at 12{mu}m in 47 Tuc (Ramdani+, 2001)J/other/Sci/292.2290 : Chandra compact binaries in 47 Tuc (Grindlay+, 2001)J/ApJ/559/1060 : Variables in 47 Tuc (Albrow+, 2001)J/AJ/125/197 : CN abundances of the 47 Tuc main sequence (Harbeck+, 2003)J/AJ/127/1588 : 47 Tuc main-sequence star abundances (Briley+, 2004)J/ApJ/625/796 : X-ray sources in the globular cluster 47 Tuc (Heinke+, 2005)J/AJ/135/1551 : Abundances of stars in 47 Tuc (Koch+, 2008)J/A+A/537/A2 : 8.6um imaging of 47 Tuc (Momany+, 2012)J/AJ/143/50 : White dwarfs in 47 Tuc (NGC 104) with HST (Woodley+, 2012)J/A+A/549/A41 : Horizontal branch stars in 47 Tuc and M5 (Gratton+, 2013)J/A+A/550/A34 : Abundances of red giants in M4 and 47 Tuc (Carretta+, 2013)J/A+A/565/A121 : Abundances of 47 Tuc turn-off stars (Dobrovolskas+, 2014)J/A+A/572/A108 : 47 Tuc red giants chemical composition (Thygesen+, 2014)J/ApJ/780/94 : Abundances of red giants in 47 Tuc (Cordero+, 2014)J/ApJ/797/124 : AGB and RGB stars in 47 Tuc (Lapenna+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/459/610https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/459/610http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/459/610https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/459/610https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/459/610http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/459/610GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/459/610/table1 (Coordinates, basic photometric data and radial velocities for the stars in the field of view of 47 Tucanae)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/459/610/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/459/610/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/459/610/table1?GETtext/xml+votable180.050000true6.0075-71.99950.0055555555555555566/33321 33323https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/459/610?format=asciiOpticaldefaultJ/MNRAS/459/610/table1Coordinates, basic photometric data and radial velocities for the stars in the field of view of 47 TucanaeDEJ2000Declination (J2000)pos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (N104a-NNNNNN)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainBmagLandolt B magnitude corrected for differential reddeningmagphot.mag;em.opt.BfloatVmagLandolt V magnitude corrected for differential reddeningmagphot.mag;em.opt.VfloatRVRadial velocitykm/sphys.veloc;pos.heliocentricfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/459/610/table2Adopted atmospheric parameters and inferred chemical abundances of 47 TucanaerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameNamemeta.id;meta.maincharTeffEffective temperature (adopted parameter)Kphys.temperature.effectiveintloggSurface gravity (adopted parameter)log(cm.s**-2)phys.gravityfloatxitMicroturbulent velocity (adopted parameter)km/sphys.velocfloat[Fe/H]Metallicity (adopted parameter)phys.abund.Zfloat[C/Fe]? [C/Fe] abundancephys.abundfloatnullable[N/Fe]? [N/Fe] abundancephys.abundfloatnullable[Na/Fe]LTE? LTE [Na/Fe] abundancephys.abundfloatnullable[Na/Fe]NLTE? NLTE [Na/Fe] abundancephys.abundfloatnullable[Mg/Fe]? [Mg/Fe] abundancephys.abundfloatnullable[Al/Fe]? [Al/Fe] abundancephys.abundfloatnullable[Si/Fe]? [Si/Fe] abundancephys.abundfloatnullable[Ni/Fe]? [Ni/Fe] abundancephys.abundfloatnullable