YOUNG STELLAR CLUSTERS CONTAINING MASSIVE YOUNG STELLAR OBJECTS IN THE VVV SURVEY

Journal Article · Thu Sep 01 00:00:00 EDT 2016 · Astronomical Journal (Online)

DOI:https://doi.org/10.3847/0004-6256/152/3/74· OSTI ID:22662963

Borissova, J.; Alegría, S. Ramírez; Kurtev, R.; Medina, N.; Navarro, C.; Kuhn, M.; Gromadzki, M.; Retamales, G.; Fernandez, M. A.; Agurto-Gangas, C.; Amigo, P. ^[1]; Alonso, J.; Decany, I. ^[2]; Lucas, P. W.; Pena, C. Contreras; Thompson, M. A. ^[3]; Chené, A. -N. ^[4]; Minniti, D. ^[5]; Catelan, M. ^[6]; Morales, E. F. E., ^[7]

---

1. Instituto de Física y Astronomía, Universidad de Valparaíso, Av. Gran Bretaña 1111, Playa Ancha, Casilla 5030 (Chile)
2. Millennium Institute of Astrophysics (MAS), Santiago (Chile)
3. Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom)
4. Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, HI 96720 (United States)
5. Departamento de Ciencias Físicas, Universidad Andres Bello, Republica 220, Santiago (Chile)
6. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile)
7. Max-Planck-Institute for Astronomy (Germany)

The purpose of this research is to study the connections of the global properties of eight young stellar clusters projected in the Vista Variables in the Via Lactea (VVV) ESO Large Public Survey disk area and their young stellar object (YSO) populations. The analysis is based on the combination of spectroscopic parallax-based reddening and distance determinations with main-sequence and pre-main-sequence ishochrone fitting to determine the basic parameters (reddening, age, distance) of the sample clusters. The lower mass limit estimations show that all clusters are low or intermediate mass (between 110 and 1800  M {sub ⊙}), the slope Γ of the obtained present-day mass functions of the clusters is close to the Kroupa initial mass function. The YSOs in the cluster’s surrounding fields are classified using low resolution spectra, spectral energy distribution fits with theoretical predictions, and variability, taking advantage of multi-epoch VVV observations. All spectroscopically confirmed YSOs (except one) are found to be massive (more than 8 M {sub ⊙}). Using VVV and GLIMPSE color–color cuts we have selected a large number of new YSO candidates, which are checked for variability and 57% are found to show at least low-amplitude variations. In few cases it was possible to distinguish between YSO and AGB classifications on the basis of light curves.

• OSTI ID: 22662963
• Journal Information: Astronomical Journal (Online), Vol. 152, Issue 3; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CLASSIFICATION
COLOR
DIAGRAMS
ENERGY SPECTRA
MASS
RESOLUTION
STAR CLUSTERS
STAR EVOLUTION
VARIABLE STARS
VARIATIONS
VISIBLE RADIATION