[GKD2002] 218 , the SIMBAD biblio

2002A&A...381..862G - Astronomy and Astrophysics, volume 381, 862-883 (2002/1-3)

Three stellar associations and their field east of LMC 4 in the Large Magellanic Cloud.

GOULIERMIS D., KELLER S.C., DE BOER K.S., KONTIZAS M. and KONTIZAS E.

Abstract (from CDS):

We present BVR photometry in an area of 20.5'x20.5' centered on LH 95 situated to the north-east of the super-bubble LMC 4. We investigate the stellar content of three stellar associations (LH 91, LH 91-I & LH 95) and their surrounding fields. Our observations use the R-Hα colour index to identify the Be star population of the region. We find that Be stars exist in all three of the investigated associations. Within LH 95 we find a central cluster of four Be stars which strongly determine the HII emissivity in this area. We estimated the reddening and the age of the systems based on isochrone fitting. The reddening was found to vary between E(B-V)≃0.15 and 0.20mag. All systems were found to be younger than 10Myr, while the field is older than ∼50Myr. We also present the luminosity and mass functions of the systems, as well as that of the field. It was found that the luminosity function slope s of the field is steeper than that of the systems, which were found to be s≃0.12-0.32. The MF slopes were estimated for both systems and field by directly counting stars between evolutionary tracks. We verify that the MF slopes of the systems are rather shallower than the ones of the field. The MF slopes of the systems lie in the range -1.0<Γ←2.0, while those of various fields are significantly steeper, around Γ≃-4.0. LH 95 was found to be probably under disruption. We discuss the possibility that this association is in the process of dissipation.

Abstract Copyright:

Journal keyword(s): Magellanic Clouds - stars: emission-line, Be - formation - C-M diagrams - luminosity function, mass function - HII regions - ISM: individual objects: DEM L 251, DEM L 252 - open clusters and associations: individual: LH 91, LH 91 I, LH 95

Nomenclature: Table 1: [GKD2002] NNNN N=21 among (Nos 12-1388).

Simbad objects: 32

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