Abundance Analysis of Turn-Off and Early Subgiant Stars in the Globular Cluster 47 Tuc (NGC 104)

Abstract

We used the UVES spectrograph on Kueyen (VLT UT2) to perform the abundance analysis of stars at the base of the giant branch (RGB) and at the main sequence turn-off in the globular cluster 47 Tuc (NGC 104). High dispersion spectra (R ~ 40,000) for 3 dwarfs and 9 subgiants were analyzed. We found an overall [Fe/H] value of -0.67 +/-0.01 +/-0.04, rms=0.05 dex. The mean value obtained from stars at the base of the RGB is virtually the same as that obtained from the dwarfs. Na and O abundances show a star-to-star scatter and are anti-correlated, not unlike previous finding in more metal-poor clusters. The extension of the anticorrelation is not as extreme as found in other clusters, but it is clearly present in unevolved stars. Al abundances do not show a significant spread; this could be indicative that p-captures in high temperature regions are less likely to occur in metal-rich clusters. The [alpha/Fe] ratios suggest a slight excess of Ti with respect to field stars of similar metallicities. Finally, we found an enhanced odd-even effect for Fe-group elements. In particular, the [Mn/Fe] ratio is almost 0.2 dex deficient with respect to the mean value of the dissipative component of field stars in the solar neighborhood. While the theoretical and observational framework for Mn is still poorly understood, the chemistry of 47 Tuc, coupled with its kinematics and its somewhat younger age, might give hints favouring an origin in a formely independent, possibly larger, subsystem of our Galaxy.

19 pages, 9 figures, accepted for publication on Astronomy & Astrophysics

References in corpus (4)

• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• Abundances for metal-poor stars with accurate parallaxes I. Basic data
• Distances and ages of NGC 6397, NGC 6752 and 47 Tuc
• Experimental f-value and isotopic structure for the Ni I line blended with [OI] at 6300A

Cited by in corpus (107)

• Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
• Na-O Anticorrelation and HB. VII. The chemical composition of first and second-generation stars in 15 globular clusters from GIRAFFE spectra
• Intrinsic iron spread and a new metallicity scale for Globular Clusters
• Properties of stellar generations in Globular Clusters and relations with global parameters
• Population Synthesis in the Blue IV: Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations
• A Comparison of Elemental Abundance Ratios in Globular Clusters, Field Stars, and Dwarf Spheroidal Galaxies
• Abundances in a Large Sample of Stars in M3 and M13
• Analysis and calibration of CaII triplet spectroscopy of Red Giant Branch stars from VLT/FLAMES observations
• Na-O Anticorrelation And HB I. The Na-O anticorrelation in NGC 2808
• Abundances of C, N, O in slightly evolved stars in the globular clusters NGC 6397, NGC 6752 and 47 Tuc
• Abundances In Very Metal Poor Dwarf Stars
• Looking outside the Galaxy: the discovery of chemical anomalies in 3 old Large Magellanic Cloud clusters
• The chemical composition of red giant stars in four intermediate-age clusters of the Large Magellanic Cloud
• The calibration of the RGB Tip as a Standard Candle: Extension to Near Infrared colors and higher metallicity
• Measuring Ages and Elemental Abundances from Unresolved Stellar Populations: Fe, Mg, C, N, and Ca
• Secondary star formation within massive star clusters: Origin of multiple stellar populations in globular clusters
• Chemical Compositions of Red Giant Stars in Old Large Magellanic Cloud Globular Clusters
• Mining SDSS in search of Multiple Populations in Globular Clusters
• Discovery of Carbon/Oxygen depleted Blue Straggler Stars in 47 Tucanae: the chemical signature of a mass-transfer formation process
• Abundances in red giant stars of NGC 2808 and correlations between chemical anomalies and global parameters in globular clusters
• Li in NGC 6752 and the formation of globular clusters
• Detailed Abundances for a Large Sample of Giant Stars in the Globular Cluster 47 Tucanae (NGC 104)
• New Light on the Formation and Evolution of M31 and its Globular Cluster System
• A large stellar evolution database for population synthesis studies. IV. Integrated properties and spectra
• A new abundance scale for the globular cluster 47 Tuc
• Globular Cluster Abundances from High-Resolution Integrated Light Spectra, I: 47 Tuc
• Detailed abundance analysis from integrated high-dispersion spectroscopy: Globular clusters in the Fornax Dwarf Spheroidal
• M31 Globular Cluster Abundances from High-Resolution, Integrated-Light Spectroscopy
• Na-O Anticorrelation and HB. VI. The chemical composition of the peculiar bulge globular cluster NGC 6388
• Blue Straggler Stars in the Unusual Globular Cluster NGC 6388
• Low-resolution spectroscopy of main sequence stars belonging to 12 Galactic globular clusters. I. CH and CN band strength variations
• Ba stars and other binaries in first and second generation stars in globular clusters
• Calcium and light-elements abundance variations from high resolution spectroscopy in globular clusters
• Constraining stellar population models - I. Age, metallicity, and abundance pattern compilation for Galactic globular clusters
• Stellar Population Models and Individual Element Abundances II: Stellar Spectra and Integrated Light Models
• Manganese trends in a sample of thin and thick disk stars. The origin of Mn
• Globular Cluster and Galaxy Formation: M31, the Milky Way and Implications for Globular Cluster Systems of Spiral Galaxies
• The formation of multiple populations in the globular cluster 47 Tuc
• A Large Sample Study of Red Giants in the Globular Cluster Omega Centauri (NGC 5139)
• Fundamental parameters, integrated RGB mass loss and dust production in the Galactic globular cluster 47 Tucanae
• High-resolution spectroscopy of the old open cluster Collinder 261:abundances of Iron and other elements
• Manganese in dwarf spheroidal galaxies
• Chemical composition of the old globular clusters NGC 1786, NGC 2210 and NGC 2257 in the Large Magellanic Cloud
• Lithium and proton-capture elements in Globular Cluster dwarfs: the case of 47 Tuc
• Revisiting nucleosynthesis in globular clusters: the case of NGC 2808 and the role of He and K
• Angular Momentum Transport by Internal Gravity Waves II- Pop II stars from the Li plateau to the horizontal branch
• AGB Sodium Abundances in the Globular Cluster 47 Tucanae (NGC 104)
• O and Na abundance patterns in open clusters of the Galactic disk
• Variations in the lithium abundances of turn off stars in the globular cluster 47 Tuc
• The chemical composition of red giants in 47 Tucanae I: Fundamental parameters and chemical abundance patterns
• An aluminium tool for multiple stellar generations in the globular clusters 47 Tuc and M 4
• The age of 47Tuc from self-consistent isochrone fits to colour-magnitude diagrams and the eclipsing member V69
• Three discrete groups with homogeneous chemistry along the red giant branch in the globular cluster NGC 2808
• The link between chemical anomalies along the red giant branch and the horizontal branch extension in globular clusters
• The Origin and Chemical Evolution of the Exotic Globular Cluster NGC3201
• O, Na, Ba and Eu abundance patterns in open clusters
• Li - O anti-correlation in NGC 6752: evidence for Li-enriched polluting gas
• The chemical composition of the low-mass Galactic globular cluster NGC 6362
• Outer Versus Inner Halo Globular Clusters: NGC 7492 Abundances
• Lithium abundances in red giants of M4: evidence for asymptotic giant branch star pollution in globular clusters?
• The Rise of the AGB in the Galactic Halo: Mg Isotopic Ratios and High Precision Elemental Abundances in M71 Giants
• Multiple stellar populations and their evolution in globular clusters: A nucleosynthesis perspective
• Potassium in globular cluster stars: comparing normal clusters to the peculiar cluster NGC 2419
• Star-to-star Na and O abundance variations along the red giant branch in NGC 2808
• Chemical Abundances for Evolved Stars in M5: Lithium through Thorium
• On the radial distribution of stars of different stellar generations in the globular cluster NGC 3201
• The COMBS survey I: Chemical Origins of Metal-Poor Stars in the Galactic Bulge
• Spectrum Syntheses of High Resolution Integrated Light Spectra of Galactic Globular Clusters
• Globular Cluster Abundances from High-Resolution, Integrated-Light Spectroscopy. II. Expanding the Metallicity Range for Old Clusters and Updated Analysis Techniques
• Chemical Abundances for Seven Giant Stars in M68 (NGC 4590) : A Globular Cluster with Abnormal Silicon and Titanium Abundances
• Chemical Complexity in the Eu-enhanced Monometallic Globular Cluster NGC 5986
• Abundances on the Main Sequence of Omega Centauri
• Differential chemical abundance analysis of a 47 Tuc AGB star with respect to Arcturus
• The WAGGS project - II. The reliability of the calcium triplet as a metallicity indicator in integrated stellar light
• A New Definition for the Ca4227 Feature: Is Calcium Really Underabundant in Early-type Galaxies?
• An Overview of the Rotational Behavior of Metal--Poor Stars
• UBVI CCD Photometry of the Old Open Cluster Berkeley 17
• Mn, Cu and Zn abundances in barium stars and their correlations with neutron capture elements
• Weighing stars: the identification of an Evolved Blue Straggler Star in the globular cluster 47 Tucanae
• A wide angle view of the Sagittarius dwarf Spheroidal Galaxy. I: VIMOS photometry and radial velocities across Sgr dSph major and minor axis
• Models for the lithium abundances of multiple populations in globular clusters and the possible role of the Big Bang lithium
• Stroemgren - near-infrared photometry of the Baade's Window. I. The bulge globular cluster NGC6528 and the surrounding field
• The VMC Survey. XI. Radial Stellar Population Gradients in the Galactic Globular Cluster 47 Tucanae
• Excess of Ca (and Sc) produced in globular cluster multiple populations: a first census in 77 Galactic globular clusters
• Optimal Integrated Abundances for Chemical Tagging of Extragalactic Globular Clusters
• Binary interactions as a possible scenario for the formation of multiple stellar populations in globular clusters
• The Chemical Composition of Red Giant Branch Stars in the Galactic Globular Clusters NGC 6342 and NGC 6366
• Predicting the frequencies of diverse exo-planetary systems
• Chemistry of multiple stellar populations in the mono-metallic, in situ, bulge globular cluster NGC 6388
• Multiple Stellar Populations of Globular Clusters From Homogeneous Ca-CN-CH-NH Photometry. VII. Metal-Poor Populations in 47 Tucanae (NGC 104)
• Cluster AgeS Experiment (CASE): Deficiency of observed dwarf novae in globular clusters
• Stellar populations in star clusters
• Fluorine Abundances in the Globular Cluster M 4
• Chemical analysis of eight giant stars of the globular cluster NGC 6366
• Models for Metal-Poor Stars with Different Initial Abundances of C, N, O, Mg, and Si. II. Application to the Colour-Magnitude Diagrams of the Globular Clusters 47 Tuc, NGC 6362, M5, M3, M55, and M92
• The Celestial Buffet: multiple populations and globular cluster formation in dwarf galaxies
• Sulphur in the Globular Clusters 47 Tucanae and NGC 6752
• The in situ origin of the globular cluster NGC 6388 from abundances of Sc, V, and Zn of a large sample of stars
• The Chemical Evolution of Globular Clusters - II. Metals and Fluorine
• Metallicity of the globular cluster NGC 6388 from high resolution spectra of more than 160 giant stars
• Multiple stellar populations at less evolved stages-II: no evidence of significant helium spread among NGC 1846 dwarfs
• Modelling of integrated-light spectra from the optical to the near-infrared: the globular cluster G280 in M31
• Mass transfer of low-mass binaries and chemical anomalies among unevolved stars in globular clusters
• Synthetic spectroscopic indices for identifying multiple stellar populations in globular clusters
• Dynamical mixing of two stellar populations in globular clusters
• The odd bunch: chrono-chemo-dynamics of sixteen unusual stars from Kepler
• The SAPP pipeline for the determination of stellar abundances and atmospheric parameters of stars in the core program of the PLATO mission