The abundance distribution and luminosity function of globular clusters in NGC 1399

Integrated Washington photometry has been obtained for the globular cluster system of NGC 1399, the central elliptical galaxy in the Fornax cluster. A new integrated metallicity index is defined which is about three times more sensitive to metal abundance than the previous such Washington index. Abundances accurate to 0.3 dex are derived for about 150 of the brightest globular clusters. The clusters have a broad, flattened abundance distribution with a mean metallicity of (Fe/H) = - 0.85 + or - 0.1, 0.75 dex more metal-poor than the halo. A significant fraction of the clusters have an approximately solar abundance, while virtually no clusters exist with (Fe/H) less than - 2. The luminosity function as determined for about 600 clusters clearly shows a turnover at T(1) = 23.0 + or - 0.15 or V = 23.45 + or - 0.16. A distance modulus of 31.0 + or - 0.25 is determined for Fornax, 0.5 + or - 0.2 mag closer than Virgo. 31 refs