Quantitative Morphological Analysis of the HDF--North and HDF-South. I. Early- and Late-type Luminosity-Size Relations of galaxies out to z~1

Abstract

Based on drizzled F606W and F814W images, we present quantitative structural parameters in the V-band rest-frame for all galaxies with z<1 and I_814(AB)<24.5 mag in the Hubble Deep Fields North and South. Our structural parameters are based on a two-component surface brightness distribution using a Sersic bulge and an exponential disc. Detailed simulations and comparisons with previous work are presented. The luminosity-size distribution of early-type galaxies is consistent with the hypothesis that their structural properties were already in place by z~1 and have evolved passively since then; early-type galaxies were ~1.35(+-0.1) mag brighter in rest-frame V-band luminosity at z~0.7 than now. Compared to present day late-type galaxies, those at z~0.7 with L_V>0.2x10^{10} h^{-2} L_sun show a moderate decrease (~30(+-10)%) in size (or interpreted differently, a decrease of ~0.77(+-0.30) mag in the central surface brightness) at a given luminosity. Finally, we make a comparison of our results with the infall and hierarchical models.

16 pages, 12 figures, MNRAS, in press