Early-type galaxies in the Hubble Deep Field:: The ⟨μe⟩-re relation and the lack of large galaxies at high redshift

We present the results of detailed surface photometry of a sample of early-type galaxies in the Hubble Deep Field (HDF). Effective radii, surface brightnesses, and total V-606 magnitudes have been obtained, as well as U-300, B-450, I-814, J, H, and K colors, which are compared with the predictions of chemical spectrophotometric models of population synthesis. Spectroscopic redshifts are available for 23 objects. For the other 25, photometric redshifts are given. In the [mu(e)]-r(e) plane, the early-type galaxies of the HDF turn out to follow the "rest frame" Kormendy relation once the appropriate K- and evolutionary corrections are applied. This evidence, linked to the dynamical information gathered by Steidel et al., indicates that these galaxies, even at z similar or equal to 2-3, lie in the fundamental plane in a virial equilibrium condition. At the same redshifts a statistically significant lack of large galaxies (i.e., with log r(e)(kpc) > 0.2) is observed.