J/A+A/564/L9 Near-IR photometry in VVV CL08 (Ramirez Alegria+, 2014)
Massive open star clusters using the VVV survey.
III: 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.
<Astron. Astrophys. 564, L9 (2014)>
=2014A&A...564L...9R 2014A&A...564L...9R
ADC_Keywords: Clusters, open ; Positional data ; Photometry, infrared
Keywords: stars: early-types - stars: massive - Galaxy: disk -
open clusters and associations: individual VVV CL086 -
techniques: photometric - techniques: spectroscopic
Abstract:
Young massive clusters are key to map the Milky Way's structure, and
near-IR large area sky surveys have contributed strongly to the
discovery of new obscured massive stellar clusters.
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.
We physically characterized the cluster using JHKs 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.
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 B0V. According
to our analysis, this young cluster (1.0Myr<age<5.0Myr) is located at
a distance of 11kpc, and we estimate a lower limit for the cluster
total mass of 2800 solar masses. It is likely that the cluster
contains even earlier and more massive stars.
Description:
Near infrared (J, H and Ks) photometry for the cluster most probable
members. We use the VVV-SkZ pipeline (Mauro et al.
2013RMxAA..49..189M 2013RMxAA..49..189M), to measure the photometry over the VVV stacked
images.
We determine the most probable members using the decontamination
algorithm from Bonatto & Bica (2010A&A...516A..81B 2010A&A...516A..81B), as described by
Borissova et al. (2011, Cat. J/A+A/532/A131).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
members.dat 65 306 VVV CL086 star positions and magnitudes
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See also:
J/A+A/532/A131 : New Galactic star clusters in VVV survey (Borissova+, 2011)
Byte-by-byte Description of file: members.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right ascension (J2000.0)
11- 20 F10.6 deg DEdeg Declination (J2000.0)
22- 28 F7.4 mag Jmag VISTA J magnitude
30- 35 F6.4 mag e_Jmag Uncertainty on J magnitude
37- 43 F7.4 mag Hmag VISTA H magnitude
45- 50 F6.4 mag e_Hmag Uncertainty on H magnitude
52- 58 F7.4 mag Ksmag VISTA Ks magnitude
60- 65 F6.4 mag e_Ksmag Uncertainty on Ks magnitude
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Acknowledgements:
Sebastian Ramirez Alegria, sebis.ramirez(at)uv.cl,
Andre-Nicolas Chene, andre-nicolas.chene(at)nrc.ca
References:
Chene et al., Paper I 2012A&A...545A..54C 2012A&A...545A..54C
Chene et al., Paper II 2013A&A...549A..98C 2013A&A...549A..98C
(End) Sebastian Ramirez Alegria [UdV, Chile], Patricia Vannier [CDS] 24-Mar-2014