Near IR imaging of Centaurus group dwarf elliptical galaxies

Abstract

Detailed studies of dwarf galaxies in the Local Group have revealed an amazing diversity in their star formation histories. Young and intermediate-age stellar populations are observed in some gas-poor dwarf ellipticals, like Fornax and Carina, where naively one would have expected to find preferentially old stellar populations. There are evidences that the environment might drive the evolution of these galaxies. In order to explore stellar populations in dwarf galaxies in an environment denser than that of the Local Group we have observed 14 dwarf elliptical galaxies in Centaurus group in near-IR Js and Ks bands. The intrinsic properties of these galaxies, the metallicities and ages of their stellar populations and the presence or absence of bright, intermediate-age AGB stars will be correlated with extrinsic properties like the local galaxy density. Here we summarize our observations, present the sample and show near-IR color-magnitude diagrams and luminosity functions for ESO269-066 and AM1343-452 dwarf galaxies.