The metallicity of Palomar 1
Abstract
Palomar 1 is a peculiar galactic globular cluster, suspected to be younger than the bulk of the Galactic halo objects. However, such a low age can be confirmed only after a reliable determination of the metallicity. In the present paper, we use the equivalent widths (W) of the Ca II triplet on medium resolution spectra in order to determine the metal content of Pal 1. From the comparison of the luminosity corrected W's in four stars of Palomar 1 with those of a sample of stars in each of three calibration clusters (M2, M15, and M71), we derive [Fe/H]=-0.6+/-0.2 on the Zinn & West (1984) scale or [Fe/H]=-0.7+/-0.2 on the Carretta & Gratton (1997) scale. We also obtain a radial velocity Vr=-82.8+/-3.3 Km/s for Pal 1.
Cite
@article{arxiv.astro-ph/9710243,
title = {The metallicity of Palomar 1},
author = {A. Rosenberg and G. Piotto and I. Saviane and A. Aparicio and R. Gratton},
journal= {arXiv preprint arXiv:astro-ph/9710243},
year = {2009}
}
Comments
15 pages, 9 figures, 3 tables. To be published in the Astronomical Journal