Bibcode
Piatti, Andrés E.; Sarajedini, Ata; Geisler, Doug; Gallart, Carme; Wischnjewsky, Marina
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 382, Issue 3, pp. 1203-1212.
Fecha de publicación:
12
2007
Número de citas
30
Número de citas referidas
27
Descripción
Colour-magnitude diagrams in the Washington system are presented for the
first time for five star clusters projected on to the outer region of
the Small Magellanic Cloud (SMC). The clusters are found to have ages in
the range 0.1-1.0 Gyr, as derived from the fit of isochrones with Z =
0.004. This sample increases substantially the number of young clusters
in the outer SMC - particularly in the south-east quadrant - with
well-derived parameters. We combine our results with those for other
clusters in the literature to derive as large and homogeneous a data
base as possible (totalling 49 clusters) in order to study global
effects. We find no conclusive evidence for a dispersion in the cluster
ages and metallicities as a function of their distance from the galaxy
centre, in the SMC outer region. L114 and 115, although very distant,
are very young clusters, lying in the bridge of the SMC and therefore
most likely formed during the interaction which formed this feature. We
also find very good agreement between the cluster age-metallicity
relation (AMR) and the prediction from a bursting model from Pagel &
Tautvaišienė with a burst that occurred 3 Gyr ago. Comparing
the present cluster AMR with that derived by Harris & Zaritsky for
field stars in the main body of the SMC, we find that field stars and
clusters underwent similar chemical enrichment histories during
approximately the last couple of Gyr, but their chemical evolution was
clearly different between 4 and 10 Gyr ago.