TY - JOUR
T1 - Lithium and proton-capture elements in globular cluster dwarfs
T2 - The case of 47 TUC
AU - D'Orazi, Valentina
AU - Lucatello, Sara
AU - Gratton, Raffaele
AU - Bragaglia, Angela
AU - Carretta, Eugenio
AU - Shen, Zhixia
AU - Zaggia, Simone
PY - 2010
Y1 - 2010
N2 - Previous surveys in a few metal-poor globular clusters (GCs) showed that the determination of abundances for Li and proton-capture elements offers a key tool to address the intracluster pollution scenario. In this Letter, we present Na, O, and Li abundances in a large sample of dwarf stars in the metal-rich GC 47 Tucanae. We found a clear Na-O anticorrelation, in good agreement with what obtained for giant members by Carretta et al. While lithium and oxygen abundances appear to be positively correlated with each other, there is a large scatter, well exceeding observational errors, and no anticorrelation with sodium. These findings suggest that Li depletion, due to mechanisms internal to the stars (which are cooler and more metal-rich than those on the Spite plateau), combines with the usual pollution scenario responsible for the Na-O anticorrelation.
AB - Previous surveys in a few metal-poor globular clusters (GCs) showed that the determination of abundances for Li and proton-capture elements offers a key tool to address the intracluster pollution scenario. In this Letter, we present Na, O, and Li abundances in a large sample of dwarf stars in the metal-rich GC 47 Tucanae. We found a clear Na-O anticorrelation, in good agreement with what obtained for giant members by Carretta et al. While lithium and oxygen abundances appear to be positively correlated with each other, there is a large scatter, well exceeding observational errors, and no anticorrelation with sodium. These findings suggest that Li depletion, due to mechanisms internal to the stars (which are cooler and more metal-rich than those on the Spite plateau), combines with the usual pollution scenario responsible for the Na-O anticorrelation.
KW - Globular clusters: individual (NGC 104)
KW - Stars: abundances
KW - Stars: individual (Population II)
UR - http://www.scopus.com/inward/record.url?scp=77950215199&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/713/1/L1
DO - 10.1088/2041-8205/713/1/L1
M3 - Article
AN - SCOPUS:77950215199
SN - 2041-8205
VL - 713
JO - The Astrophysical Journal Letters
JF - The Astrophysical Journal Letters
IS - 1 PART 2
ER -