Abstract
We present spectroscopic observations of 72 early-type galaxies in the core of the Coma cluster. Our sample includes 36 dwarf galaxies (dE/dS0) for which we measured velocity dispersion and line strength indices. We confirm that the Faber-Jackson relation holds for the luminous early-type galaxies. However, lower luminosity early-type galaxies follow a different relation: L ∝ σ^{2}. We show that rotation alone cannot be responsible for this change of slope. We also derive ages, metallicities and [α/Fe] ratios for this sample of galaxies.
