Obscured clusters.IV. The most massive stars in [DBS2003]179

TL;DR

This study characterizes the massive stars in the young galactic cluster DBS2003 179, revealing its stellar content, physical parameters, and evidence of ongoing star formation nearby, confirming its status as a young, massive cluster near the Galactic center.

Contribution

First detailed spectroscopic analysis of the massive stellar population in DBS2003 179, providing physical parameters and insights into its star formation environment.

Findings

Contains three late WN or WR/LBV stars with masses above 85Msun

Includes at least 5 OIf and 5 OV stars with masses between 20-80Msun

Cluster mass estimated at approximately 2.5 x 10^4 Msun

Abstract

Aims. We report new results for the massive evolved and main sequence members of the young galactic cluster DBS2003 179. We determine the physical parameters and investigate the high-mass stellar content of the cluster, as well as of its close vicinity. Methods. Our analysis is based on ISAAC/VLT moderate-resolution (R\approx4000) infrared spectroscopy of the brightest cluster members. We derive stellar parameters for sixteen of the stellar members, using full non-LTE modeling of the obtained spectra. Results. The cluster contains three late WN or WR/LBV stars (Obj 4, Obj 15, and Obj 20:MDM32) and at least 5 OIf and 5 OV stars. According to the Hertzsprung-Russell diagram for DBS2003 179, the WR stars show masses above 85Msun, the OIf stars are between 40 and 80Msun, and the main sequence O stars are >20Msun. There are indications of binarity for Obj 4 and Obj 11, and Obj 3 shows a variable spectrum. The cluster is surrounded by a continuous protostar formation region most probably triggered by DBS2003 179. Conclusions. We confirm that DBS2003 179 is young massive cluster (2.5 10^4Msun) very close to the Galactic center at the distance of 7.9+-0.8 kpc.