SCYON Abstract

Received on December 5 2006

Chemical Homogeneity in Collinder 261 and Implications for Chemical Tagging

AuthorsG.M. De Silva (1), K.C. Freeman (2), J. Bland-Hawthorn (3), M. Asplund (2), M.S. Bessell (2), and R. Collet (4)
Affiliation
(1) European Southern Observatory, Alonso de Cordova 3107, Santiago, Chile
(2) Mount Stromlo Observatory, Australian National University, Weston ACT 2611, Australia
(3) Anglo-Australian Observatory, Eastwood NSW 2122, Australia
(4) Uppsala Astronomical Observatory, Sweden
Accepted byAstronomical Journal
Contactgdesilva@eso.org
URLhttp://www.arxiv.org/abs/astro-ph/0611832
Links Collinder 261

Abstract

This paper presents abundances for 12 red giants of the old open cluster Collinder 261 based on spectra from VLT/UVES. Abundances were derived for Na, Mg, Si, Ca, Mn, Fe, Ni, Zr and Ba. We find the cluster has a solar-level metallicity of [Fe/H] = -0.03 . However some alpha elements were found to be enhanced. The star-to-star scatter was consistent with the expected measurement uncertainty for all elements. The observed rms scatter is as follows: Na = 0.07, Mg = 0.05, Si = 0.06, Ca = 0.05, Mn = 0.03, Fe = 0.02, Ni = 0.04, Zr = 0.12, and Ba = 0.03 dex. The high levels of homogeneity indicate that chemical information remains preserved in this old open cluster. We use the chemical homogeneity we have now established in Cr 261, Hyades and the HR1614 moving group to examine the uniqueness of the individual cluster abundance patterns, ie. chemical signatures. We demonstrate that the three studied clusters have unique chemical signatures, and discuss how other such signatures may be searched for in the future. Our findings support the prospect of large scale chemical tagging of disk stars to common formation sites in order to unravel the dissipative history of the Galactic disk.