The East Asian Observatory SCUBA--2 survey of the COSMOS field:
  unveiling 1147 bright sub-millimeter sources across 2.6 square degrees
  We present sensitive 850$\mu$m imaging of the COSMOS field using 640hr 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 $\sigma_{850\mu{\mathrm{m}}}$=1.2mJy/beam over an area of
1.6 sq. degree (MAIN; HST/ACS footprint), and
$\sigma_{850\mu{\mathrm{m}}}$=1.7mJy/beam over an additional 1 sq. degree of
supplementary (SUPP) coverage. We present a catalogue of 1020 and 127 sources
detected at a significance level of >4$\sigma$ and >4.3$\sigma$ in the MAIN and
SUPP regions, respectively, corresponding to a uniform 2% false-detection rate.
We construct the single-dish 850$\mu$m number counts at $S_{850}$>2mJy 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 $S_{850}$=2-10mJy 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$\pm$0.2 galaxies within a 13$''$ radius
(~100kpc at $z$~2). The bulk of these galaxies represent near-infrared-selected
SMGs and/or spatially-correlated sources and lie at a median photometric
redshift of $z$=2.0$\pm$0.1. Finally, we perform a stacking analysis at
sub-millimeter and far-infrared wavelengths of stellar-mass-selected galaxies
($M_{\star}$=10$^{10}$-10$^{12}{\rm M_{\odot}}$) from $z$=0-4, obtaining
high-significance detections at 850um in all subsets (SNR=4-30), and
investigate the relation between far-infrared luminosity, stellar mass, and the
peak wavelength of the dust SED. The publication of this survey adds a new
deep, uniform sub-millimeter layer to the wavelength coverage of this
well-studied COSMOS field.
