Program: GS-2009A-Q-25

The aim of this proposal is to continue with the first spectroscopic study of the faint galaxy content of the Antlia cluster. This galaxy cluster is the nearest one (d=35 Mpc) after Virgo and Fornax. While intermediate in richness between these two other clusters, its galaxy density is even higher. However, the Antlia cluster had been hardly studied in the optical until we started with the first deep CCD photometric galaxy survey, which is the basis of this follow-up spectroscopic study. We have shown that Antlia early-type galaxies follow a tight color-magnitude relation. Recently, an extension of four magnitudes, towards the faint end of such relation, has been achieved thanks to radial velocities measured from GMOS-spectra obtained in 2008A. Three new GMOS fields are now requested, to obtain kinematics for some 30 dwarf galaxy candidates in Antlia, down to R_T= 21 mag. Several UCD and globular cluster candidates located in the same fields will be included. First scientific objec tives deal with membership and, for a brighter subsample, with dwarf population properties. Once a significant sample of radial velocities is gathered, it will be useful for studying the dwarfs' luminosity function, environmental properties, its formation mechanisms and the cluster dynamics and evolution.