The East Asian Observatory SCUBA-2 Survey of the COSMOS Field: Unveiling 1147 Bright Sub-millimeter Sources across 2.6 Square Degrees

Abstract

Abstract We present sensitive 850 μm imaging of the Cosmological Evolution Survey (COSMOS) field using 640 hr of new and archival observations taken with SCUBA-2 at the East Asian Observatory’s James Clerk Maxwell Telescope. The SCUBA-2 COSMOS survey (S2COSMOS) achieves a median noise level of σ 850μm = 1.2 mJy beam−1 over an area of 1.6 sq. degree (main; Hubble Space Telescope/Advanced Camera for Surveys footprint), and σ 850μm = 1.7 mJy beam−1 over an additional 1 sq. degree of supplementary (supp) coverage. We present a catalog of 1020 and 127 sources detected at a significance level of >4σ and >4.3σ in the main and supp regions, respectively, corresponding to a uniform 2% false-detection rate. We construct the single-dish 850 μm number counts at S 850 > 2 mJy and show that these S2COSMOS counts are in agreement with previous single-dish surveys, demonstrating that degree-scale fields are sufficient to overcome the effects of cosmic variance in the S 850 = 2–10 mJy population. To investigate the properties of the galaxies identified by S2COSMOS sources we measure the surface density of near-infrared-selected galaxies around their positions and identify an average excess of 2.0 ± 0.2 galaxies within a 13″ radius (∼100 kpc at z ∼ 2). The bulk of these galaxies represent near-infrared-selected submillimeter galaxies and/or spatially correlated sources and lie at a median photometric redshift of z = 2.0 ± 0.1. Finally, we perform a stacking analysis at submillimeter and far-infrared wavelengths of stellar-mass-selected galaxies (M ⋆ = 1010–1012 M ⊙) from z = 0–4, obtaining high-significance detections at 850 μm in all subsets (signal-to-noise ratio, S/N = 4–30), and investigate the relation between far-infrared luminosity, stellar mass, and the peak wavelength of the dust spectral energy distribution. The publication of this survey adds a new deep, uniform submillimeter layer to the wavelength coverage of this well-studied COSMOS field.