Massive open star clusters using the VVV survey III. A young massive cluster at the far edge of the Galactic bar

Ramirez Alegria, S.; Borissova, J.; Chene, A. N.; O'Leary, E.; Amigo, P.; Minniti, D.; Saito, R. K.; Geisler, D.; Kurtev, R.; Hempel, M.; Gromadzki, M.; Clarke, J. R. A.; Negueruela, I.; Marco, A.; Fierro, C.; Bonatto, C.; Catelan, M.

Abstract

Context. Young massive clusters are key to map the Milky Way's structure, and near-infrared large area sky surveys have contributed strongly to the discovery of new obscured massive stellar clusters. Aims. We present the third article in a series of papers focused on young and massive clusters discovered in the VVV survey. This article is dedicated to the physical characterization of VVV CL086, using part of its OB-stellar population. Methods. We physically characterized the cluster using JHK(s) near-infrared photometry from ESO public survey VVV images, using the VVV-SkZ pipeline, and near-infrared K-band spectroscopy, following the methodology presented in the first article of the series. Results. Individual distances for two observed stars indicate that the cluster is located at the far edge of the Galactic bar. These stars, which are probable cluster members from the statistically field-star decontaminated CMD, have spectral types between O9 and B0 V. According to our analysis, this young cluster (1.0 Myr < age < 5.0 Myr) is located at a distance of 11(-6)(+5) kpc, and we estimate a lower limit for the cluster total mass of (2.8(-1.4)(+1.6))center dot 10(3) M-circle dot. It is likely that the cluster contains even earlier and more massive stars.

Más información

Título según WOS: Massive open star clusters using the VVV survey III. A young massive cluster at the far edge of the Galactic bar
Título según SCOPUS: Massive open star clusters using the VVV survey: III. A young massive cluster at the far edge of the Galactic bar
Título de la Revista: ASTRONOMY & ASTROPHYSICS
Volumen: 564
Editorial: EDP SCIENCES S A
Fecha de publicación: 2014
Idioma: English
DOI:

10.1051/0004-6361/201322619

Notas: ISI, SCOPUS - ISI