Near-infrared photometry and spectroscopy of the low Galactic latitude globular cluster 2MASS-GC 03

Abstract

We present deep near-infrared photometry and spectroscopy of the globular cluster 2MASSGC 03 projected in the Galactic disc using MMT and Magellan Infrared Spectrograph on the Clay Telescope (Las Campanas Observatory) and VISTA Variables in the Via Lactea Survey data. Most probable cluster member candidates were identified from near-infrared photometry. Out of 10 candidates that were followed-up spectroscopically, 5 have properties of cluster members, from which we calculate 〈[Fe/H]〉= - 0.9 ± 0.2 and a radial velocity of 〈vr〉 = - 78 ± 12 km s-1. A distance of 10.8 kpc is estimated from three likely RR Lyrae members. Given that the cluster is currently at a distance of 4.2 kpc from the Galactic Centre, the cluster's long survival time of an estimated 11.3 ± 1.2 Gyr strengthens the case for its globular-cluster nature. The cluster has a hint of elongation in the direction of the Galactic Centre.