The spatial distributions and intrinsic shapes of dwarf elliptical galaxies in the Virgo and Fornax Clusters

Data from deep photographic surveys of the Fornax and Virgo Clusters show that the projected radial number density profile of dwarf ellipticals in these clusters depends both on luminosity and on the presence or absence of nucleation. All nucleated dE's and the nonnucleated dE's that are fainter than MBT_ ~ -14. 2 are concentrated toward the centers of clusters like the giant E and S0 galaxies. In contrast, nonnucleated dE's brighter than MBT_ ~ 14. 2 are distributed like the spirals and irregulars. Furthermore, the flattening distribution of bright nonnucleated dE's is similar to that of the dwarf irregulars, but differs from the flattening distribution of either the nucleated dwarfs (dE, N) or of the giant ellipticals. The similarity of flattenings of dE (bright, no N) and Im types removes one of the previous objections to the hypothesis that some dwarf ellipticals could be stripped Im's. However, the data are also consistent with stochastic self-propagating star-formation models of irregular galaxies.