The SCUBA-2 Cosmology Legacy Survey: the EGS deep field – I. Deep number counts and the redshift distribution of the recovered cosmic infrared background at 450 and 850 μ m
Year: 2016
Type: article
Abstract: We present deep observations at 450 and 850 μm in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of σ450 = 1.2 mJy beam−1 and σ850 = 0.2 mJy beam−1. We detect 57 sources at 450 μm and 90 at 850 μm with signal-to-noise ratio >3.5 over ∼70 arcmin2. From these detections, we derive the number counts at flux densities S450 > 4.0 mJy and S850 > 0.9 mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24 μm-selected galaxies through a stacking technique, which add a total of 0.26 ± 0.03 and 0.07 ± 0.01 MJy sr−1, at 450 and 850 μm, respectively. These surface brightnesses correspond to 60 ± 20 and 50 ± 20 per cent of the total CIB measurements, where the errors are dominated by those of the total CIB. Using the photometric redshifts of the 24 μm-selected sample and the redshift distributions of the submillimetre galaxies, we find that the redshift distribution of the recovered CIB is different at each wavelength, with a peak at z ∼ 1 for 450 μm and at z ∼ 2 for 850 μm, consistent with previous observations and theoretical models.
Institutions: National Institute of Astrophysics, Optics and Electronics, University of Hertfordshire, University of Bristol, National Research Council Canada, Dalhousie University, Durham University, Imperial College London, Royal Observatory, University of Edinburgh, Virginia Tech, European Southern Observatory, University of Hawaii at Hilo, Large Synoptic Survey Telescope Corporation, UK Astronomy Technology Centre, University of British Columbia, University of Groningen, Leiden University, Leiden Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: Imperial College Astrophysics & Space Physics Consolidated Grant April 2013 - March 2016, G4081850257, Characterising the interstellar medium of bright, lensed, star-forming galaxies across cosmic time, Research in planetary formation, astrophysics, and cosmology at Bristol, Astronomy and Astrophysics at Edinburgh, PATT travel support for Bristol Astrophysics and Planetary Studies, Research in planetary formation, astrophysics, and cosmology at Bristol, PATT travel grant support for Bristol Astrophysics and Planetary Studies, Imperial College Astrophysics PATT Linked Grant
OpenAlex ID: W2596898567