Discovery of new Milky Way star cluster candidates in the 2MASS point source catalog

III. Follow-up observations of cluster candidates in the Galactic Center region

¹ Pontificia Universidad Católica de Chile, Facultad de Física, Departamento de Astronomía y Astrofísica, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile e-mail: dante@astro.puc.cl
² European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei Munchen, Germany e-mail: [jborisso;vivanov]@eso.org
³ Grupo de Astronomía, Departamento de Física, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile e-mail: doug@kukita.cfm.udec.cl
⁴ Princeton University Observatory, Peyton Hall, Ivy Lane, Princeton, NJ 08544-1001, USA e-mail: stephens@astro.princeton.edu

Received: 19 August 2004
Accepted: 28 December 2004

Abstract

This paper is part of a project to search the inner Milky Way for hidden massive clusters and to address the question of whether our Galaxy still forms clusters similar to the progenitors of the present-day globular clusters.
We report high angular resolution deep near-infrared imaging of 21 cluster candidates selected from the catalogues of Bica et al. (2003a, A&A, 397, 177) and Dutra et al. (2003a, A&A, 400, 533) in a region around the Galactic Center. These catalogues were created from visual inspection of the 2MASS images. Seven objects appear to be genuine clusters, and for these objects we present estimates of extinction, distance and in some cases age and mass. 
Our estimated masses range from 1200 to 5500 . These clusters are thus significantly smaller than any Galactic globular cluster, and indicate that the formation of massive young clusters such as Arches and Quintuplet is not common in the present-day Milky Way.
The remaining 14 objects are either not clusters or cannot be classified based on our data.