Evidence Hub

The Metallicity Distribution Function of Omega Centauri

Peter M. Frinchaboy, Jaehyon Rhee, James C. Ostheimer, Steven R. Majewski, Richard J. Patterson, Winfrey Y. Johnson, Dana Dinescu, Christopher Palma et al.

arXiv, 2001

Abstract

We explore the metallicity distribution function (MDF) of red giant stars in Omega Centauri from a catalogue of Washington M, T_2 and DDO51 photometry covering over 1.1 deg^2 outside the cluster core. Using updated calibrations of giant branch isometallicity loci in this filter system, photometric metallicities, guided by previously published spectroscopic abundances, are derived. Several methods are employed to correct the MDF for contamination by Galactic stars, including: (1) use of the surface gravity sensitivity of the (M-DDO51) color index to eliminate foreground dwarf stars, (2) radial velocities, and (3) membership probabilities from proper motions. The contamination-corrected MDF for Omega Cen shows a range of enrichment levels spanning nearly 2 dex in [Fe/H], and with peaks at [Fe/H]=-1.6, -1.2, and -0.9.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free