A population of binaries in the Asymptotic Giant Branch of 47 Tucanae?

Abstract

We have used a set of archived Hubble Space Telescope/ACS images to probe the evolved populations of the globular cluster 47 Tucanae. We find an excess of Asymptotic Giant Branch (AGB) stars in the cluster core. We interpret this feature as the signature of an extra-population likely made by the progeny of massive stars originated by the evolution of binary systems. Indeed the comparison with theoretical tracks suggests that the AGB population of 47 Tuc can be significantly contaminated by more massive stars currently experiencing the first ascending Red Giant Branch.

arXiv comment14 pages, 4 figures, in press on ApJ Letters

References in corpus (12)

• The Photometric Performance and Calibration of the HST Advanced Camera For Surveys
• A large stellar evolution database for population synthesis studies. II. Stellar models and isochrones for an alpha-enhanced metal distribution
• The giant, horizontal and asymptotic branches of galactic globular clusters. I. The catalog, photometric observables and features
• Observations of 20 millisecond pulsars in 47 Tucanae at 20 cm
• High Resolution X-ray Imaging of a Globular Cluster Core: Compact Binaries in 47Tuc
• Transforming observational data and theoretical isochrones into the ACS/WFC Vega-mag system
• Discovery of Carbon/Oxygen depleted Blue Straggler Stars in 47 Tucanae: the chemical signature of a mass-transfer formation process
• The contribution of primordial binaries to the blue straggler population in 47 Tucanae
• Blue Stragglers, Young White Dwarfs and UV-excess stars in the core of 47 Tuc
• Discovery of another peculiar radial distribution of Blue Stragglers in Globular Clusters: The case of 47 Tuc
• A Far-Ultraviolet Survey of 47 Tucanae. I. Imaging
• Heavy Element Abundances in Giant Stars of 47 Tuc

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