Infrared surveys of Galactic star clusters

Many attempts have been made to carry out a complete observational census of Milky Way star clusters based on recent near- and mid-infrared surveys. However, more clusters are still being discovered, indicating that existing catalogs are incomplete. We attempt to estimate the total number of supermassive (SM; Mcl ≥ 104 M⊙) clusters in the Galaxy, and to improve the yield from the automated cluster searches. Assuming that the ‘local’ census of SM clusters is complete, and that their surface density accross the disk follows that of the stars, we predict that the Milky Way contains ≥81 ± 21 SM clusters. We apply a cluster-detection algorithm to the 2mass Point Source Catalog after a preliminary color and/or magnitude selection of the point sources to improves the surface-density cluster-to-field contrast. Our algorithm identified 94 new candidates, and re-identified 34 known clusters. During the visual inspection, we detected an additional 41 new candidates, and re-identified 32 known objects. Preliminary characterization suggests that the new list may contain red-supergiant, open and globular clusters.