Red, redder, reddest: SCUBA-2 imaging of colour-selected \textit{Herschel} sources

Abstract

High-redshift, luminous, dusty star forming galaxies (DSFGs) constrain the extremity of galaxy formation theories. The most extreme are discovered through follow-up on candidates in large area surveys. Here we present 850 $\mu$m SCUBA-2 follow-up observations of 188 red DSFG candidates from the \textit{Herschel} Multi-tiered Extragalactic Survey (HerMES) Large Mode Survey, covering 274 deg${}^2$. We detected 87 per cent with a signal-to-noise ratio $>$ 3 at 850~$\mu$m. We introduce a new method for incorporating the confusion noise in our spectral energy distribution fitting by sampling correlated flux density fluctuations from a confusion limited map. The new 850~$\mu$m data provide a better constraint on the photometric redshifts of the candidates, with photometric redshift errors decreasing from ${\sigma }_z/(1+z)\approx 0.21$ to $0.15$. Comparison spectroscopic redshifts also found little bias ($⟨(z-z_{\mathrm{spec}})/(1+z_{\mathrm{spec}})⟩=0.08$). The mean photometric redshift is found to be 3.6 with a dispersion of $0.4$ and we identify 21 DSFGs with a high probability of lying at $z>4$. After simulating our selection effects we find number counts are consistent with phenomenological galaxy evolution models. There is a statistically significant excess of WISE-1 and SDSS sources near our red galaxies, giving a strong indication that lensing may explain some of the apparently extreme objects. Nevertheless, our sample should include examples of galaxies with the highest star formation rates in the Universe ($\gg 10^3$ M${}_{\odot }$yr${}^{-1}$).

22 pages, 14 figures and 3 tables

References in corpus (27)

• Cosmic Star Formation History
• The Cosmic Evolution Survey (COSMOS) -- Overview
• A Dust-Obscured Massive Maximum-Starburst Galaxy at a Redshift of 6.34
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• The Detection of a Population of Submillimeter-Bright, Strongly-Lensed Galaxies
• The SCUBA-2 Cosmology Legacy Survey: 850um maps, catalogues and number counts
• The SCUBA HAlf Degree Extragalactic Survey (SHADES) - III. Identification of radio and mid-infrared counterparts to submillimetre galaxies
• SCUBA-2: iterative map-making with the Sub-Millimetre User Reduction Facility
• The Mean Star Formation Rate of X-ray selected Active Galaxies and its Evolution from z=2.5: Results from PEP-Herschel
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: High resolution 870um source counts
• The impact of clustering and angular resolution on far-infrared and millimeter continuum observations
• The SCUBA-2 Cosmology Legacy Survey: ALMA resolves the bright-end of the sub-millimeter number counts
• ISM properties of a Massive Dusty Star-Forming Galaxy discovered at z ~ 7
• The Herschel-ATLAS: a sample of 500μm-selected lensed galaxies over 600 square degrees
• The SCUBA HAlf Degree Extragalactic Survey (SHADES) -- VI. 350 micron mapping of submillimetre galaxies
• SONS: The JCMT legacy survey of debris discs in the submillimetre
• The space density of luminous dusty star-forming galaxies at $z>4$: SCUBA-2 and LABOCA imaging of ultrared galaxies from $Herschel$-ATLAS
• A joint analysis of BLAST 250--500um and LABOCA 870um observations in the Extended Chandra Deep Field South
• A dusty star-forming galaxy at z=6 revealed by strong gravitational lensing
• Rise of the Titans: A Dusty, Hyper-Luminous "870 micron Riser" Galaxy at z~6
• HerMES: The Rest-Frame UV Emission and A Lensing Model for the z=6.34 Luminous Dusty Starburst Galaxy HFLS3
• The most distant, luminous, dusty star-forming galaxies: redshifts from NOEMA and ALMA spectral scans
• What produces the far-infrared/submm emission in the most luminous QSOs?
• ALMACAL II: Extreme star-formation-rate densities in a pair of dusty starbursts at $z=3.442$ revealed by ALMA 20-milliarcsec resolution imaging
• A controlled study of cold dust content in galaxies from $z=0-2$
• Imaging the environment of a z = 6.3 submillimeter galaxy with SCUBA-2
• 3C 220.3: a radio galaxy lensing a submillimeter galaxy

Cited by in corpus (19)

• HELP: The Herschel Extragalactic Legacy Project
• COLDz: A High Space Density of Massive Dusty Starburst Galaxies ~1 Billion Years after the Big Bang
• Mapping Obscuration to Reionization with ALMA (MORA): 2mm Efficiently Selects the Highest-Redshift Obscured Galaxies
• Illuminating the dark side of cosmic star formation two billion years after the Big Bang
• The Herschel Bright Sources (HerBS): Sample definition and SCUBA-2 observations
• NOEMA redshift measurements of bright Herschel galaxies
• Towards a census of high-redshift dusty galaxies with $Herschel$: A selection of "500 $\mu$m-risers"
• Missing Giants: Predictions on Dust-Obscured Galaxy Stellar Mass Assembly Throughout Cosmic Time
• A hyperluminous obscured quasar at a redshift of z ~ 4.3
• Spitzer catalog of Herschel-selected ultrared dusty, star-forming galaxies
• ALMA unveils wider environment of distant red protocluster core
• A large population of strongly lensed faint submillimetre galaxies in future dark energy surveys inferred from JWST imaging
• The Nature of 500 micron Risers I: SMA Observations
• High-z dusty star-forming galaxies: a top-heavy initial mass function?
• High-z Sudoku: A diagnostic tool for identifying robust (sub)mm redshifts
• Early Science with the Large Millimeter Telescope: a 1.1 mm AzTEC Survey of Red-$Herschel$ dusty star-forming galaxies
• A Systematic Search for Reddest Far-infrared and Sub-millimeter Galaxies: revealing dust-embedded starbursts at high redshifts
• A SCUBA-2 Selected Herschel-SPIRE Dropout and the Nature of this Population
• Interpreting the statistical properties of high-z extragalactic sources detected by the South Pole Telescope survey