Color and Metallicity Distributions of M81 Globular Clusters

Abstract

In this paper we present catalogs of photometric and spectroscopic data for globular clusters (GCs) in M81. The catalogs include B- and V-band photometric and reddening data of 95 GCs, in addition to spectroscopic metallicities of 40 GCs. Using these data, we make some statistical correlations. The results show that the distributions of intrinsic B and V colors and metallicities are bimodal, with metallicity peaks at [Fe/H] ≈ - 1.45 and -0.53, respectively, as has been demonstrated for our Milky Way and M31. The relation between spectroscopic metallicity and intrinsic B and V color also exists as it does for the Milky Way and M31. © 2005. The Astronomical Society of the Pacific. All rights reserved.