J/ApJ/750/L14ivo://CDS.VizieR/J/ApJ/750/L14doi:10.26093/cds/vizier.17509014CDSCarretta E.Bragaglia A.Gratton R.G.Lucatello S.D'Orazi V.2023-04-20T15:51:59Z2014-01-29T08:10:00ZCDS support team

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

cds-question@unistra.frchemical-abundancesgiant-starsglobular-star-clustersWe present aluminum, magnesium, and silicon abundances in the metal-poor globular cluster NGC 6752 for a sample of more than 130 red giants with homogeneous oxygen and sodium abundances. We find that [Al/Fe] shows a spread of about 1.4 dex among giants in NGC 6752 and is anticorrelated with [Mg/Fe] and [O/Fe] and correlated with [Na/Fe] and [Si/Fe]. These relations are not continuous in nature, but the distribution of stars is clearly clustered around three distinct Al values, low, intermediate, and high. These three groups nicely correspond to the three distinct sequences previously detected using Stromgren photometry along the red giant branch. These two independent findings strongly indicate the existence of three distinct stellar populations in NGC 6752. Comparing the abundances of O and Mg, we find that the population with intermediate chemical abundances cannot originate from material with the same composition of the most O- and Mg-poor population, diluted by material with that of the most O- and Mg-rich one. This calls for different polluters.2012ApJ...750L..14Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/750/L14CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/other/Nat/498.198 : Na abundances in NGC6752 (Campbell+, 2013)J/MNRAS/423/2901 : NGC 6752 multiwavelength survey (Thomson+, 2012)J/A+A/524/A44 : CN and CH line strengths in 12 globulars (Pancino+, 2010)J/A+A/517/A81 : 2nd & 3d parameters of HB of GCs (Gratton+, 2010)J/A+A/505/139 : Abundances of red giants in 17 GCs (Carretta+, 2009)J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009)J/A+A/464/927 : Abundances of red giants in NGC 6752 (Carretta+, 2007)J/AJ/130/1693 : HST-ACS observations of 5 globular clusters (Brown+, 2005)J/A+A/440/901 : Reddening and metallicity of NGC 6752 (Gratton, 2005)J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/750/L14https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/750/L14http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/750/L14https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/750/L14https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/750/L14http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/750/L14GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/750/L14/table1 ([Mg/Fe], [Al/Fe], and [Si/Fe] ratios for red giants in NGC 6752)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/750/L14/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/750/L14/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/750/L14/table1?GETtext/xml+votable180.050000true288.0030833333-60.00329166670.0055555555555555566/47125 47168https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/750/L14?format=asciidefaultJ/ApJ/750/L14/table1[Mg/Fe], [Al/Fe], and [Si/Fe] ratios for red giants in NGC 6752recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1217/48975] Star identification number (1)meta.id;meta.maininto_[Mg/Fe][0/3] Number of lines used to determine [Mg/Fe]meta.numberint[Mg/Fe][0.07/0.6]? Log of Mg to Fe abundancelog(Sun)phys.abund.Fefloatnullablee_[Mg/Fe][0.004/0.3]? Error in [Mg/Fe]log(Sun)stat.error;phys.abundfloatnullableo_[Al/Fe][0/2] Number of lines used to determine [Al/Fe]meta.numberint[Al/Fe][-0.21/1.6]? Log of Al to Fe abundancelog(Sun)phys.abund.FefloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchare_[Al/Fe][0.004/0.3]? Error in [Al/Fe]log(Sun)stat.error;phys.abundfloatnullableo_[Si/Fe][0/11] Number of lines used to determine [Si/Fe]meta.numberint[Si/Fe][0.3/0.6]? Log of Si to Fe abundancelog(Sun)phys.abund.Fefloatnullablee_[Si/Fe][0.004/0.3]? Error in [Si/Fe]log(Sun)stat.error;phys.abundfloatnullableAl[0/1] Al flag; 1=detection, 0=upper limitmeta.code.multipintPop[EIP-] Population group flag from this paper (2)meta.id.parentchar_RAPositions from Carretta et al., 2007, Cat. J/A+A/464/927 (right ascension part)degpos.eq.ra;meta.main_DEPositions from Carretta et al., 2007, Cat. J/A+A/464/927 (declination part)degpos.eq.dec;meta.main