Age -- Metallicity relation in the MCs clusters (Based on observations
  made with the Danish 1.54 m and ESO 3.6m Telescopes at La Silla Observatory,
  Chile)
  Aims: To investigate a possible dependence between age and metallicity in the
Magellanic Clouds (MCs) from a study of small open star clusters, using
Str\"{o}mgren photometry. Our goal is to trace evidence of an age metallicity
relation (AMR) and correlate it with the mutual interactions of the two MCs.
Our aim is also to correlate the AMR with the spatial distribution of the
clusters. In the Large Magellanic Cloud (LMC), the majority of the selected
clusters are young (up to 1 Gyr) and our aim is to search for an AMR at this
epoch which has not been much studied. Methods: We report on results for 15 LMC
and 8 Small Magellanic Cloud (SMC) clusters, scattered all over the area of
these galaxies, to cover a wide spatial distribution and metallicity range. The
selected LMC clusters were observed with the 1.54m Danish Telescope in Chile,
using the Danish Faint Object Spectrograph and Camera (DFOSC) with a single
2kx2k CCD, whereas the SMC clusters were observed with the ESO 3.6m Telescope
also in Chile with the ESO Faint Object Spectrograph and Camera (EFOSC). The
obtained frames were analysed with the conventional DAOPHOT and IRAF software.
We used Str\"{o}mgren filters in order to achieve reliable metallicities from
photometry. Isochrone fitting was used in order to determine the ages and
metallicities. Results: The AMR for the LMC displays a metallicity gradient,
with higher metallicities for the younger ages. The AMR for LMC-SMC star
clusters shows a possible jump in metallicity and a considerable increase at
about 6x10^8 yr. It is possible that this is connected to the latest LMC-SMC
interaction. The AMR for the LMC also displays a metallicity gradient with
distance from the centre. The metallicities in SMC are lower, as expected for a
metal poor host galaxy.
