Constraints on the early formation of field elliptical galaxies

We present the results of an HK' wide-field survey encompassing the Hubble Deep Field and its flanking fields. Our wide-field survey provides uniform coverage of a 61.8 arcmin(2) area to a depth equivalent to K = 20.1 at 5 si gma. We have also imaged the Hubble Deep Field in HK', providing uniform co verage of a 7.8 arcmin(2) area to a depth equivalent to K = 21.2 at 5 sigma . Using these data in combination with new deep University of Hawaii 8K V a nd I imaging obtained on the Canada-France-Hawaii Telescope, we find only a small population of objects with colors redder than an equivalent I-K = 4, the color expected for an evolved elliptical galaxy at z > 1. We infer tha t only a fraction of the local field elliptical galaxy population with M-K < -23.4 could have formed in single bursts at high redshift.