An ALMA survey of sub-millimetre Galaxies in the Extended Chandra Deep Field South: the far-infrared properties of SMGs
Journal article, 2014

We exploit Atacama Large Millimeter Array (ALMA) 870 mu m observations of sub-millimetre sources in the Extended Chandra Deep Field South to investigate the far-infrared properties of high-redshift sub-millimetre galaxies (SMGs). Using the precisely located 870 mu m ALMA positions of 99 SMGs, together with 24 mu m and radio imaging, we deblend the Herschel/SPIRE imaging to extract their far-infrared fluxes and colours. The median redshifts for ALMA LESS (ALESS) SMGs which are detected in at least two SPIRE bands increases with wavelength of the peak in their spectral energy distributions (SEDs), with z = 2.3 +/- 0.2, 2.5 +/- 0.3 and 3.5 +/- 0.5 for the 250, 350 and 500 mu m peakers, respectively. 34 ALESS SMGs do not have a >3 sigma counterpart at 250, 350 or 500 mu m. These galaxies have a median photometric redshift derived from the rest-frame UV-mid-infrared SEDs of z = 3.3 +/- 0.5, which is higher than the full ALESS SMG sample; z = 2.5 +/- 0.2. We estimate the far-infrared luminosities and characteristic dust temperature of each SMG, deriving L-IR = (3.0 +/- 0.3) x 10(12) L-circle dot (SFR = 300 +/- 30 M-circle dot yr(-1)) and T-d = 32 +/- 1 K. The characteristic dust temperature of these high-redshift SMGs is Delta T-d = 3-5K lower than comparably luminous galaxies at z = 0, reflecting the more extended star formation in these systems. We show that the contribution of S-870 mu m >= 1 mJy SMGs to the cosmic star formation budget is 20 per cent of the total over the redshift range z similar to 1-4. Adopting an appropriate gas-to-dust ratio, we estimate a typical molecular mass of the ALESS SMGs of M-H2 = (4.2 +/- 0.4) x 10(10) M-circle dot. Finally, we show that SMGs with S-870 mu m > 1 mJy (L-IR greater than or similar to 10(12) L-circle dot) contain similar to 10 per cent of the z similar to 2 volume-averaged H-2 mass density.

number counts


similar-to 2

molecular gas

star-forming galaxies


degree extragalactic survey

galaxies: high-redshift

luminosity function

ultraluminous galaxies


galaxies: starburst

large array

galaxies: evolution


A. M. Swinbank

Durham University

J. M. Simpson

Durham University

I. Smail

Durham University

C. M. Harrison

Durham University

J. A. Hodge

Max Planck Society

A. Karim

University of Bonn

F. Walter

Max Planck Society

D. M. Alexander

Durham University

W. N. Brandt

Pennsylvania State University

C. De Breuck

European Southern Observatory (ESO)

E. da Cunha

Max Planck Society

S. C. Chapman

Dalhousie University

K. E. K. Coppin

University of Hertfordshire

A. L. R. Danielson

Durham University

H. Dannerbauer

University of Vienna

R. Decarli

Max Planck Society

T. R. Greve

University College London (UCL)

R. J. Ivison

University of Edinburgh

Kirsten Kraiberg Knudsen

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

C. D. P. Lagos

European Southern Observatory (ESO)

E. Schinnerer

Max Planck Society

A. P. Thomson

Durham University

J. L. Wardlow

Niels Bohr Institute

A. Weiss

Max Planck Society

P. van der Werf

Leiden University

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 438 2 1267-1287 stt2273

Subject Categories

Astronomy, Astrophysics and Cosmology



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