J/ApJ/713/L1 Lithium and proton-capture elements in 47 Tuc (D'Orazi+, 2010) ================================================================================ Lithium and proton-capture elements in globular cluster dwarfs: the case of 47 Tuc. D'Orazi V., Lucatello S., Gratton R., Bragaglia A., Carretta E., Shen Z., Zaggia S. =2010ApJ...713L...1D ================================================================================ ADC_Keywords: Abundances ; Clusters, globular ; Effective temperatures ; Stars, dwarfs Keywords: globular clusters: individual (NGC 104) - stars: abundances - stars: individual (Population II) Abstract: 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. (2009, Cat. J/A+A/505/117). 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. Description: We retrieved from the ESO Archive FLAMES-Giraffe spectra (MEDUSA configuration) of 109 unevolved members of the metal-rich GC 47 Tuc (Program 081.D-0287; PI: Z. Shen). The observations were carried out in Service mode in 2008 August-September; gratings HR15n (R~17000), HR18 (R~18400), and HR20A (R~16000) were used to cover LiI (6707{AA}), OI (7771, 7773, 7774{AA}), and NaI (8183, 8194{AA}) features, respectively. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 80 100 Properties of target stars -------------------------------------------------------------------------------- See also: VII/202 : Globular Clusters in the Milky Way (Harris, 1997) J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009) J/A+A/503/545 : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009) J/AJ/135/1551 : Abundances of stars in 47 Tuc (Koch+, 2008) J/AJ/125/197 : CN abundances of the 47 Tuc main sequence (Harbeck+, 2003) J/A+AS/117/227 : Dwarf effective temperatures (Alonso+ 1996) J/A+AS/106/161 : (V,I) photometry in NGC 6356 and 47 Tuc (Bica+ 1994) J/ApJS/85/293 : HST Observations of core of 47 Tuc (de Marchi+ 1993) J/PASP/99/739 : BV photometry in 4 fields of 47 Tuc (Hesser+, 1987) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- ID [1/114] Stellar identification number (<[DLG2010] NNN> in Simbad) 5- 11 F7.5 deg RAdeg Right Ascension (J2000) 13- 20 F8.4 deg DEdeg Declination (J2000) 22- 27 F6.3 mag Vmag The V band magnitude (1) 29- 34 F6.3 mag Bmag The B band magnitude (1) 36- 39 I4 K Teff Effective temperature (1) 41- 44 F4.2 [cm/s2] log(g) Log of the gravity 46- 50 F5.3 [-] lognO ?=9.999 Log of the oxygen number abundance (2) 52- 56 F5.3 [-] e_lognO ?=9.999 Error in LognO 58- 62 F5.3 [-] lognNa ?=9.999 Log of the sodium number abundance (2) 64- 68 F5.3 [-] e_lognNa ?=9.999 Error in LognNa 70- 74 F5.3 [-] lognLi ?=9.999 Log of the lithium number abundance (2) 76- 80 F5.3 [-] e_lognLi ?=0.000 Error in LognLi -------------------------------------------------------------------------------- Note (1): We obtained initial effective temperatures (T_eff_) from the de-reddened (E(B-V)=0.04; Harris 1996, see Cat. VII/202) B-V colors (data are from unpublished photometry by Y. Momany (2004, private communication) and the calibration by Alonso et al. (1996, Cat. J/A+AS/117/227). The adopted values were derived from a relation between V magnitude and color-based T_eff_. See section 2 for further details. Note (2): the Solar values are: lognO = 8.79; lognNa = 6.21; lognLi = 2.78+/-0.08 -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Apr-2012