We confront predictions of the currently popular theories for dE formation and evolution with the observed position of dEs in log LB vs. log σ, log LB vs. loge, log LB vs. log Ie, and log Re vs. log Ie diagrams and in the (log σ, log Re, log Ie) parameter space in which bright and intermediate-luminosity elliptical galaxies and bulges of spirals define a Fundamental Plane (FP). We show that the dE sequences in the various univariate diagrams are disjunct from those traced by bright and intermediate-luminosity elliptical galaxies and bulges of spirals. It appears that semi-analytical models (SAMs) that incorporate quiescent star formation with an essentially z-independent star-formation efficiency, combined with post-merger starbursts and the dynamical response after supernova-driven gas-loss, are able to reproduce the position of the dEs in the various univariate and bivariate diagrams.
Proceedings of the International Astronomical Union,
Vol. 1, pp. 316-321