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arXiv · 1209.6370

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

J. Borissova·L. Georgiev·M. M. Hanson·J. R. A. Clarke·R. Kurtev·V. D. Ivanov·F. Penaloza·D. J. Hillier·J. Zsargo
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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.

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J. Borissova, L. Georgiev, M. M. Hanson, J. R. A. Clarke, R. Kurtev, V. D. Ivanov, F. Penaloza, D. J. Hillier, J. Zsargo. 2012-09-27. Obscured clusters.IV. The most massive stars in [DBS2003]179. https://doi.org/10.1051/0004-6361%2F201118348

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