B, V and I photometry of the intermediate metallicity bulge globular clusters NGC 6325 and NGC 6355

Abstract

Colour-Magnitude Diagrams are presented for the globular clusters NGC 6325 and NGC 6355. These clusters are embedded in crowded bulge fields. Both clusters are concentrated and have blue Horizontal Branches, and NGC 6325 shows a blue tail. We derive a reddening E(B−V) 0:95 and a distance from the Sun d 6:9 kpc for NGC 6325, and E(B−V) 0:78 and d 8:8 kpc for NGC 6355. They are both at 1 kpc from the Galactic center, above the plane. The metallicity has been estimated based on red giant branch morphology, being consistent with an intermediate metallicity of [Fe=H] −1:3 for both clusters, at the lower end of the metallicity distribution of bulge field stars. They add to the list of blue Horizontal Branch clusters with intermediate metallicities within the bulge volume.