Evolution and color dependence of the galaxy angular correlation function: 350,000 galaxies in 5 square degrees

When applied to deep photometric catalogs, the two-point angular correlation function, omega(theta), is a sensitive probe of the evolution of galaxy clustering properties. Here we present measurements of omega(theta) as a function of I-AB magnitude and (R - I) color to a depth of I-AB = 24 on scales theta = 7" - 3', using a sample of similar to350,000 galaxies covering 5 deg(2) in total over five separate fields. Using redshifts of 2954 galaxies in early DEEP2 Galaxy Redshift Survey data, we construct robust galaxy redshift distributions as a function of I-AB magnitude and (R - I) color for galaxies in the range 0 < z < 2. We constrain models of the redshift evolution of galaxy clustering and find that significant growth of clustering has occurred from z greater than or equal to 1 to z = 0. A model in which the comoving scale length, x(0), evolves linearly with redshift, x(0)(z) = x(0)(0)( 1 - Bz), fits the data better than the epsilon model proposed by Groth & Peebles. The clustering properties depend strongly on observed (R - I) color, with both the reddest and bluest galaxies exhibiting large clustering amplitudes and steeper slopes. Different observed ( R - I) color ranges are sensitive to very disparate redshift regimes. Red galaxies with (R - I) similar to 1.5 lie in a narrow redshift range centered at z similar to 0.85 and have a comoving scale length of clustering at z = 0.85 of x(0) = 5.0 +/- 0.3 h(-1) Mpc. These galaxies have early-type spectra and are likely progenitors of massive local ellipticals. The bluest galaxies with (R - I) similar to 0 appear to be a mix of star-forming galaxies, both relatively local (z similar to 0.3-0.6) dwarfs and bright z > 1.4 galaxies, as well as broad-line active galactic nuclei. We find that local blue dwarfs are relatively unclustered, with x(0) = 1.6 +/- 0.2 h(-1) Mpc. The z > 1.4 blue galaxies have a larger clustering scale length, x(0) greater than or similar to5 h(-1) Mpc.