We are using these multi-colour observations to understand the nature of the stellar populations in the dwarfs. We use a statistical method to determine the luminosity and the colour distributions of the galaxies in the clusters, based on comparing the galaxies seen towards the clusters with those galaxies seen in comparison fields. However, we have also carried out spectroscopy with the 2dF spectrograph on the Anglo-Australian Telescope on Abell 1146 and 3363. This technique will enable us to determine which of the brighter galaxies actually lie within the clusters, rather than being foreground or background objects. The large images are of giant elliptical galaxies.
Some spiral galaxies are visible.
The small, faint images are of dwarf elliptical and dwarf irregular galaxies. Click here for Steve Phillipps's account of the intermediate-redshift clusters project. Here There Be Dwarfs by S. Phillipps, J. B. Jones, S. P. Driver, W. J. Couch and R. M. Smith, published in the Anglo-Australian Observatory Newsletter , No. 84, pp. Luminosity Distributions Within Rich Clusters. I. A Ubiquitous Dwarf-Rich Luminosity Function.