Astronomy and Astrophysics, volume 298, 39-56 (1995/6-1)
A study of clusters and field stars in two regions in the Large Magellanic Cloud.II. Colour-magnitude diagrams and luminosity functions.
WESTERLUND B.E., LINDE P. and LYNGA G.
Abstract (from CDS):
The stellar populations in two regions of the Large Magellanic Cloud, one in the NW and one in the SW, are analysed to a limiting absolute visual magnitude of about MV=3.5mag Colour-magnitude diagrams are presented for three faint clusters in each region as well as for the populations in their surrounding fields. The clusters in the NW region have ages between 0.1 and 0.5Gyr and metallicities close to solar whereas those in the SW are about 1Gyr old and of lower metallicity. Also the field populations in the two regions have different characters. Both contain strong components of ages around 1 to 3Gyr. In the NW region a young component, 0.2-0.6Gyr, exists which is completely missing in the SW region. The latter contains a weak but well identified generation about 7-10Gyr old which may be traced also in the NW region. Comparisons with other regions in the Large Cloud are carried out. The SW part of the LMC differs from the others by an almost total lack of young generations. The luminosity functions in many parts of the Large Cloud are otherwise rather similar. The generations identified here confirm that the initial star formation in the LMC, more than 7Gyr ago, was weak and that a much stronger star production occurred during the period 0.5 to 4.0Gyr ago.
techniques: photometric - HR-diagram - luminosity function - Magellanic Clouds - galaxies: star clusters - galaxies: stellar content