H-ATLAS: estimating redshifts of Herschel sources from sub-mm fluxes

E. A. Pearson, S. Eales, L. Dunne, J. Gonzalez-Nuevo, S. Maddox, J. E. Aguirre, M. Baes, A. J. Baker, N. Bourne, C. M. Bradford, C. J. R. Clark, A. Cooray, A. Dariush, G. De Zotti, S. Dye, D. Frayer, H. L. Gomez, A. I. Harris, R. Hopwood, E. IbarR. J. Ivison, M. Jarvis, M. Krips, A. Lapi, R. E. Lupu, M. J. Michalowski, M. Rosenman, D. Scott, E. Valiante, I. Valtchanov, P. van der Werf, J. D. Vieira

Research output: Contribution to journalArticlepeer-review

Abstract

Upon its completion, the Herschel Astrophysics Terahertz Large Area Survey (H-ATLAS) will be the largest sub-millimetre survey to date, detecting close to half-a-million sources. It will only be possible to measure spectroscopic redshifts for a small fraction of these sources. However, if the rest-frame spectral energy distribution (SED) of a typical H-ATLAS source is known, this SED and the observed Herschel fluxes can be used to estimate the redshifts of the H-ATLAS sources without spectroscopic redshifts. In this paper, we use a sub-set of 40 H-ATLAS sources with previously measured redshifts in the range 0.5 <z <4.2 to derive a suitable average template for high-redshift H-ATLAS sources. We find that a template with two dust components (T-c = 23.9 K, T-h = 46.9 K and ratio of mass of cold dust to mass of warm dust of 30.1) provides a good fit to the rest-frame fluxes of the sources in our calibration sample. We use a jackknife technique to estimate the accuracy of the redshifts estimated with this template, finding a root mean square of delta z/(1 + z) = 0.26. For sources for which there is prior information that they lie at z > 1, we estimate that the rms of delta z/(1 + z) = 0.12. We have used this template to estimate the redshift distribution for the sources detected in the H-ATLAS equatorial fields, finding a bimodal distribution with a mean redshift of 1.2, 1.9 and 2.5 for 250, 350 and 500 mu m selected sources, respectively.
Original languageEnglish
Pages (from-to)2753-2763
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Volume435
Issue number4
DOIs
Publication statusPublished - Nov 2013

Keywords

  • galaxies: high-redshift
  • galaxies: photometry
  • submillimetre: galaxies
  • STRONGLY LENSED GALAXIES
  • SUBMILLIMETER GALAXIES
  • STAR-FORMATION
  • SKY SURVEY
  • COLD DUST
  • POPULATION
  • UNIVERSE
  • EVOLUTION
  • ENERGY
  • SPIRE

Fingerprint Dive into the research topics of 'H-ATLAS: estimating redshifts of Herschel sources from sub-mm fluxes'. Together they form a unique fingerprint.

Cite this