The young Galactic star cluster [DBS2003] 179

Abstract

Context. Recent near- and mid-infrared surveys have brought evidence that the Milky Way continues to form massive clusters. Aims. We carry out a program to determine the basic physical properties of the new massive cluster candidate [DBS2003] 179. Methods. Medium-resolution K-band spectra and deep near- infrared images of [DBS2003] 179 were used to derive the spectral types of eight member stars, and to estimate the distance and reddening to the cluster. Results. Seven of ten stars with spectra show emission lines. Comparison with template spectra indicated that they are early O- type stars. The mean radial velocity of the cluster is V-rad = -77 +/- 6 km s(-1). Knowing the spectral types of the members and the color excesses, we determined extinction A(V) similar to 16.6 and distance modulus (m - M)(0) similar to 14.5 mag (D similar to 7.9 Kpc). The presence of early O- stars and a lack of red supergiants suggests a cluster age of 2 - 5 Myr. The total cluster mass is approximated to 0.7 x 10(4) M-circle dot and it is not yet dynamically relaxed. Conclusions. The candidate [DBS2003] 179 further increases the family of the massive young clusters in the Galaxy, although it appears less massive than the prototypical starburst clusters.