The O-Na and Mg-Al Anticorrelations in Turn-Off and early Subgiants in Globular Clusters

Abstract

High dispersion spectra (R>40,000) for a quite large number of stars at the main sequence turn-off and at the base of the subgiant branch in NGC6397 and NGC6752 were obtained with the UVES on Kueyen (VLT UT2). The [Fe/H] values we found are -2.03+/-0.02+/-0.04 and -1.42+/-0.02+/-0.04 for NGC6397 and NGC6752 respectively, where the first error bars refer to internal errors and the second ones to systematic errors. In both clusters the [Fe/H] obtained for TO-stars agree perfectly (within a few per cents) with that obtained for stars at the base of the RGB. The [O/Fe]=0.21+/-0.05 value we obtain for NGC6397 is quite low, but it agrees with previous results obtained for giants in this cluster; also, the star-to-star scatter in both O and Fe is very small, indicating that this small mass cluster is chemically very homogenous. On the other side, our results show clearly and for the first time that the O-Na anticorrelation (up to now seen only for stars on the red giant branches of globular clusters) is present among unevolved stars in the globular cluster NGC6752, a more massive cluster than NGC6397. A similar anticorrelation is present also for Mg and Al, and C and N. It is very difficult to explain the observed Na-O, and Mg-Al anticorrelation in NGC6752 stars by a deep mixing scenario; we think it requires some non internal mechanism.

20 pages, A&A Latex, including 7 .ps figures, tex-macro aa.cls, uses psfig.tex. submitted to Astronomy & Astrophysics

References in corpus (6)

• Abundances for Globular Cluster Giants: I. Homogeneous Metallicities for 24 Clusters
• The Spectra of Main Sequence Stars in Galactic Globular Clusters II. CH and CN Bands in M71
• The Production of Sodium and Aluminum in Globular Cluster Red Giant Stars
• Non-LTE Abundances and Consequences for the Evolution of the alpha elements in the Galaxy
• The Spectra of Main Sequence Stars in Galactic Globular Clusters I. CH and CN Bands in M13
• Distances and ages of globular clusters using Hipparcos parallaxes of local subdwarfs

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• Models of Metal-Poor Stars with Different Initial Abundances of C, N, O, Mg, and Si. I. Bolometric Corrections Derived from New MARCS Synthetic Spectra and Their Implications for Observed Colour-Magnitude Diagrams
• The Celestial Buffet: multiple populations and globular cluster formation in dwarf galaxies
• From Theory to Observations and viceversa: theoretical uncertainties and observational constraints
• Sulphur in the Globular Clusters 47 Tucanae and NGC 6752
• AGB Stars: Summary and Warning
• Chemical analysis of the Bulge Globular Cluster NGC 6553
• Global metallicity of globular cluster stars from colour-magnitude diagrams
• Mergers all the way down: stellar collisions and kinematics of a dense hierarchically forming massive star cluster in a dwarf starburst
• Evidence of globular cluster abundance anomalies in the SMC intermediate-age cluster Kron 3
• Lithium abundances as a tracer of AGB stars pollution in the globular cluster NGC 6752
• AGB subpopulations in the nearby globular cluster NGC 6397
• Discrepancies between spectroscopy and HST photometry in tagging multiple stellar populations in 22 globular clusters
• NGC 6397: The metallicity trend along the isochrone revisited
• Atomic diffusion and mixing in old stars VII. Abundances of Mg, Ti, and Fe in M30
• Diffusion and mixing in globular clusters
• Self-enrichment in Globular Clusters: the extreme He-rich population of NGC 2808
• Models for Metal-Poor Stars with Different Initial Abundances of C, N, O, Mg, and Si. III. Grids of Isochrones for $-2.5\le$ [Fe/H] $\le -0.5$ and Helium Abundances $Y=0.25$ and $0.29$ at Each Metallicity
• Chemical evolution of star clusters
• Thermally Pulsing Asymptotic Giant Branch Star Models and Globular Cluster Planetary Nebulae I: The Model
• The effects of individual metal contents on isochrones for C, N, O, Na, Mg, Al, Si, and Fe
• Stellar abundances of beryllium and CUBES
• Tidal Interactions of Red Giants with Environment Stars in Globular Clusters
• The Galaxy Population of Abell 1367: The Stellar Mass-Metallicity Relation
• Abundance Anomalies in NGC6752 - Do AGB Stars Have a Role?
• Mass transfer of low-mass binaries and chemical anomalies among unevolved stars in globular clusters
• Omega Centauri: weak MgH-band in red giants directly trace the helium content
• Prospects of measuring a metallicity trend and spread in globular clusters from low-resolution spectroscopy
• Observations of the Hot Horizontal-Branch Stars in the Metal-Rich Bulge Globular Cluster NGC 6388 - Indications of Helium Enrichment and a Lesson in Crowded Field Spectroscopy
• Inconsistent metallicity spreads in first generation stars of globular clusters from high resolution spectroscopy and HST photometry
• Slow Cooling in Low Metallicity Clouds: An Origin of Globular Cluster Bimodality?
• The Curious Radial Distributions of Horizontal Branch Stars in NGC 6441
• The Nephele ecosystem: stars, globular clusters, and stellar streams associated with the progenitor galaxy of $\omega$ Centauri
• Physical Parameters of Stars in NGC 6397 Using ANN-Based Interpolation and Full Spectrum Fitting
• The Pristine survey. XXVI. Chemical abundances of subgiant stars of the extremelymetal-poor stream C-19
• Not-so-simple stellar populations in nearby, resolved massive star clusters
• Pinning Down Gravitational Settling