Ages and metallicities of lmc and smc red clusters through hb and g band photometry

Abstract

We present narrow band integrated photometry of the Hβ and G band absorption features for 41 LMC and 10 SMC red star clusters. An age-metallicity calibration is provided for the color-color diagram. We derive SWB types between IV and VII for 23 unclassified clusters and discuss their distribution in the age vs metallicity plane. We study the chemical evolution of the Magellanic Clouds (MC): the LMC presents a steeper chemical enrichment slope. An intrinsic metallicity dispersion is found in the LMC chemical evolution, indicating that the gas has been inhomogeneous at any time, prevailing a local enrichment over a global one. One zone models describe the evolution of both Clouds, being the efficiency of star cluster formation larger in the LMC. The LMC presents a burst of star cluster formation at t = 4.5 10⁹ yr. We also present new B – V data for fainter SMC clusters, providing an essentially complete color histogram for clusters with globular cluster appearance.