Metallicity and radial velocity of the second parameter globular cluster Terzan 1 in the galactic bulge

Abstract

Terzan 1 is the globular cluster with closest projection relative to the Galactic center. We report radial velocities and metallicities of 17 stars in order to investigate their membership in the cluster. From the 11 probable members of Terzan 1, a radial velocity of vr = 114 +- 14 km sˉ¹ is obtained. For this sample an intermediate metallicity of [Fe/H] ≈ –1.3 is found, in agreement with previous work based on HST Colour-Magnitude Diagrams.