Early-Type Galaxies in the Hubble Deep Field: The <mu_e>-r_e Relation and the Lack of Large Galaxies at High Redshift

Abstract

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 ~= 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^kpc_e>0.2) is observed.