Angular Clustering of Galaxies at 3.6 Microns from the Spitzer Wide‐area Infrared Extragalactic (SWIRE) Survey

Abstract

We present the first analysis of large-scale clustering from the Spitzer Wide-area Infrared Extragalactic legacy survey (SWIRE). We compute the angular correlation function of galaxies selected to have 3.6 μm fluxes brighter than 32 μJy in three fields totaling 2 deg 2 in area. In each field we detect clustering with a high level of significance. The amplitude and slope of the correlation function is consistent between the three fields and is modeled as w(θ) = Aθ 1-y with A = (0.6 ± 0.3) × 10 -3, γ = 2.03 ± 0.10. With a fixed slope of γ = 1.8, we obtain an amplitude of A = (1.7 ± 0.1) × 10 -3. Assuming an equivalent depth of K ≈ 18.7 mag we find that our errors are smaller but our results are consistent with existing clustering measurements in K-band surveys and with stable clustering models. We estimate our median redshift z ≃ 0.75, and this allows us to obtain an estimate of the three-dimensional correlation function ξ(r), for which we find r 0 = 4.4 ± 0.1 h -1 Mpc.