The Age and Metallicity Relation of Omega Centauri
Abstract
We present a metallicity distribution based on photometry and spectra for 442 omega Cen cluster members that lie at the main sequence turnoff region of the color-magnitude diagram. This distribution is similar to that found for the red giant branch. The distribution shows a sharp rise to a mean of [Fe/H] = -1.7 with a long tail to higher metallicities. Ages have then been determined for the stars using theoretical isochrones enabling the construction of an age-metallicity diagram. Interpretation of this diagram is complicated by the correlation of the errors in the metallicities and ages. Nevertheless, after extensive Monte-Carlo simulations, we conclude that our data show that the formation of the cluster took place over an extended period of time: the most metal-rich stars in our sample ([Fe/H] ~ -0.6) are younger by 2-4 Gyrs than the most metal-poor population.
Keywords
Cite
@article{arxiv.astro-ph/0605612,
title = {The Age and Metallicity Relation of Omega Centauri},
author = {L. M. Stanford and G. S. Da Costa and J. E. Norris and R. D. Cannon},
journal= {arXiv preprint arXiv:astro-ph/0605612},
year = {2011}
}
Comments
53 pages, 20 figures, 5 tables, accepted for publication in ApJ