The young Galactic star cluster [DBS2003]179

TL;DR

This study characterizes the young massive star cluster [DBS2003]179 in the Milky Way, revealing its spectral types, distance, age, and mass, and confirming it as a recent addition to the galaxy's population of such clusters.

Contribution

It provides the first detailed physical properties of the cluster [DBS2003]179, including spectral classification, distance, age, and mass, based on infrared spectroscopy and imaging.

Findings

Cluster contains early O-type stars.

Distance estimated at approximately 7.9 kpc.

Age inferred to be 2-5 million years.

Abstract

Recent near- and mid-infrared surveys have brought evidence that the Milky Way continues to form massive clusters. We carry out a program to determine the basic physical properties of the new massive cluster candidate [DBS2003]179. 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. 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 Vrad=-77+-6 km/s. Knowing the spectral types of the members and the color excesses, we determined extinction Av~16.6 and distance modulus (m-M)0~14.5 mag (D~7.9 kpc). The presence of early O-stars and a lack of red supergiants suggests a cluster age of 2-5Myr. The total cluster mass is approximated to 0.7x10^4 Msun and it is not yet dynamically relaxed. 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.