The DEEP2 Galaxy Redshift Survey: Clustering of Galaxies in Early Data (original) (raw)

We measure the two-point correlation function ξ(r p , π) in a sample of 2219 galaxies between z = 0.7 − 1.35 to a magnitude limit of R AB = 24.1 from the first season of the DEEP2 Galaxy Redshift Survey. From ξ(r p , π) we recover the real-space correlation function, ξ(r), which we find can be approximated within the errors by a power-law, ξ(r) = (r/r 0 ) −γ , on scales ∼ 0.1 − 10 h −1 Mpc. In a sample with an effective redshift of z eff = 0.82, for a ΛCDM cosmology we find r 0 = 3.53 ± 0.81 h −1 Mpc (comoving) and γ = 1.66 ± 0.12, while in a higher-redshift sample with z eff = 1.14 we find r 0 = 3.12 ± 0.72 h −1 Mpc and γ = 1.66 ± 0.12. These errors are estimated from mock galaxy catalogs and are dominated by the cosmic variance present in the current data sample. We find that red, absorption-dominated, passively-evolving galaxies have a larger clustering scale length, r 0 , than blue, emission-line, actively star-forming galaxies. Intrinsically brighter galaxies also cluster more strongly than fainter galaxies at z ≃ 1. Our results imply that the DEEP2 galaxies have an effective bias b = 0.96 ± 0.13 if σ 8 DM = 1 today or b = 1.19 ± 0.16 if σ 8 DM = 0.8 today. This bias is lower than what is predicted by semi-analytic simulations at z ≃ 1, which may be the result of our R-band target selection. We discuss possible evolutionary effects within our survey volume, and we compare our results with galaxy clustering studies at other redshifts, noting that our star-forming sample at z ≃ 1 has very similar selection criteria as the Lyman-break galaxies at z ≃ 3 and that our red, absorptionline sample displays a clustering strength comparable to the expected clustering of the Lyman-break galaxy descendants at z ≃ 1. Our results demonstrate that galaxy clustering properties as a function of color, spectral type and luminosity seen in the local Universe were largely in place by z ≃ 1.