Description
We present the luminosity function and color-redshift relation of a magnitude-limited sample of 145 mostly red field E/S0 galaxies at z<~1 from the DEEP Groth Strip Survey (GSS). Using nearby galaxy images as a training set, we develop a quantitative method to classify E/S0 galaxies based on smoothness, symmetry, and bulge-to-total light ratio. Using this method, we identify 145 E/S0's at 16.5<I<22 within the GSS, for which 44 spectroscopic redshifts (z_spec_) are available. Most of the galaxies with spectroscopic redshifts (86%) form a "red envelope" in the redshift-color diagram, consistent with predictions of spectral synthesis models in which the dominant stellar population is formed at redshifts z>~1.5.
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