TY - JOUR
T1 - Aluminum abundances of multiple stellar generations in the globular cluster NGC 1851
AU - Carretta, Elisa
AU - D'Orazi, V.
AU - Gratton, Raffaele G.
AU - Lucatello, Sara
PY - 2012
Y1 - 2012
N2 - We studied the distribution of aluminum abundances among red giants in the peculiar globular cluster NGC 1851. Aluminum abundances were derived from the strong doublet Al i 8772-8773 Ãmeasured on intermediate-resolution FLAMES spectra of 50 cluster stars acquired under the Gaia-ESO public survey. We coupled these abundances with previously derived abundances of O, Na, and Mg to fully characterize the interplay of the NeNa and MgAl cycles of H-burning at high temperature in the early stellar generation in NGC 1851. The stars in our sample show well-defined correlations between Al, Na and Si; Al is anticorrelated with O and Mg. The average value of the [Al/Fe] ratio steadily increases from the first generation stars to the second generation populations with intermediate and extremely modified composition. We confirm on a larger database the results recently obtained by us: the pattern of abundances of proton-capture elements implies a moderate production of Al in NGC 1851. We find evidence of a statistically significant positive correlation between Al and Ba abundances in the more metal-rich component of red giants in NGC 1851.
AB - We studied the distribution of aluminum abundances among red giants in the peculiar globular cluster NGC 1851. Aluminum abundances were derived from the strong doublet Al i 8772-8773 Ãmeasured on intermediate-resolution FLAMES spectra of 50 cluster stars acquired under the Gaia-ESO public survey. We coupled these abundances with previously derived abundances of O, Na, and Mg to fully characterize the interplay of the NeNa and MgAl cycles of H-burning at high temperature in the early stellar generation in NGC 1851. The stars in our sample show well-defined correlations between Al, Na and Si; Al is anticorrelated with O and Mg. The average value of the [Al/Fe] ratio steadily increases from the first generation stars to the second generation populations with intermediate and extremely modified composition. We confirm on a larger database the results recently obtained by us: the pattern of abundances of proton-capture elements implies a moderate production of Al in NGC 1851. We find evidence of a statistically significant positive correlation between Al and Ba abundances in the more metal-rich component of red giants in NGC 1851.
KW - Globular clusters: general
KW - Globular clusters: individual: NGC 1851
KW - Stars: abundances
KW - Stars: atmospheres
KW - Stars: Population II
UR - http://www.scopus.com/inward/record.url?scp=84863609475&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201219277
DO - 10.1051/0004-6361/201219277
M3 - Article
AN - SCOPUS:84863609475
SN - 0004-6361
VL - 543
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A117
ER -