On the redshift distribution and physical properties of ACT-selected DSFGs
Affiliation
Univ Arizona, Steward Observ, Dept AstronIssue Date
2017-01-01Keywords
galaxies: evolutiongalaxies: high-redshift
galaxies: starburst
galaxies: star formation
submillimetre: galaxies
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OXFORD UNIV PRESSCitation
On the redshift distribution and physical properties of ACT-selected DSFGs 2017, 464 (1):968 Monthly Notices of the Royal Astronomical SocietyRights
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical SocietyCollection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present multi-wavelength detections of nine candidate gravitationally lensed dusty starforming galaxies (DSFGs) selected at 218 GHz (1.4 mm) from the Atacama Cosmology Telescope (ACT) equatorial survey. Among the brightest ACT sources, these represent the subset of the total ACT sample lying in Herschel SPIRE fields, and all nine of the 218 GHz detections were found to have bright Herschel counterparts. By fitting their spectral energy distributions (SEDs) with a modified blackbody model with power-law temperature distribution, we find the sample has a median redshift of z = 4.1(-1.0)(+1.1) (68 per cent confidence interval), as expected for 218 GHz selection, and an apparent total infrared luminosity of log10(mu LIR/L-circle dot) = 13.86(-0.30)(+0.33), which suggests that they are either strongly lensed sources or unresolved collections of unlensed DSFGs. The effective apparent diameter of the sample is root mu d = 4.2(-1.0)(+1.7) kpc, further evidence of strong lensing or multiplicity, since the typical diameter of DSFGs is 1.0-2.5 kpc. We emphasize that the effective apparent diameter derives from SED modelling without the assumption of optically thin dust (as opposed to image morphology). We find that the sources have substantial optical depth (tau = 4.2(-1.9)(+3.7)) to dust around the peak in the modified blackbody spectrum (lambda(obs) <= 500 mu m), a result that is robust to model choice.ISSN
0035-87111365-2966
Version
Final published versionSponsors
National Science Foundation [AST-0955810]; U.S. National Science Foundation [AST-0408698, AST-0965625]; Princeton University; University of Pennsylvania; Canada Foundation for Innovation (CFI); CFI under Compute Canada; Government of Ontario; Ontario Research Fund - Research Excellence; University of Toronto; Moore Foundation; Norris Foundation; Associates of Caltech; state of California; state of Illinois; state of Maryland; NSF; NSF under a cooperative agreement; CARMA partner universities; Alfred P. Sloan Foundation; National Aeronautics and Space Administration; National Science Foundation; U.S. Department of Energy; Japanese Monbukagakusho; Max Planck Society; Higher Education Funding Council for England; U.S. Department of Energy Office of Science; Comision Nacional de Investigacion Cientifica y Tecnologica de Chile (CONICYT); Compute Canada; [PHY-0855887]; [PHY-1214379]Scopus Count
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