An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field-South: detection of C II at z=4.4
Artikel i vetenskaplig tidskrift, 2012

We present Atacama Large Millimeter Array (ALMA) 870-mu m (345-GHz) observations of two submillimetre galaxies (SMGs) drawn from an ALMA study of the 126 submillimetre sources from the LABOCA Extended Chandra Deep Field-South Survey (LESS). The ALMA data identify the counterparts to these previously unidentified submillimetre sources and serendipitously detect bright emission lines in their spectra which we show are most likely to be [CII] 157.74 mu m emission yielding redshifts of z = 4.42 and 4.44. This blind detection rate within the 7.5-GHz bandpass of ALMA is consistent with the previously derived photometric redshift distribution of SMGs and suggests a modest, but not dominant (less than or similar to 25 per cent), tail of 870-mu m selected SMGs at z greater than or similar to 4. We find that the ratio of L-[CII]/L-FIR in these SMGs is much higher than seen for similarly far-infrared-luminous galaxies at z similar to 0, which is attributed to the more extended gas reservoirs in these high-redshift ultraluminous infrared galaxies (ULIRGs). Indeed, in one system we show that the [C II] emission shows hints of extended emission on greater than or similar to 3 kpc scales. Finally, we use the volume probed by our ALMA survey to show that the bright end of the [CII] luminosity function evolves strongly between z = 0 and similar to 4.4, reflecting the increased interstellar medium cooling in galaxies as a result of their higher star formation rates. These observations demonstrate that even with short integrations, ALMA is able to detect the dominant fine-structure cooling lines from high-redshift ULIRGs, measure their energetics and spatially resolved properties and trace their evolution with redshift.


galaxies: evolution

ultraluminous infrared galaxies

midinfrared counterparts

galaxies: high-redshift

iso-lws spectroscopy



photodissociation regions


galaxies: starburst


laboca survey

micron line


A. M. Swinbank

University of Durham

A. Karim

University of Durham

I. Smail

University of Durham

J. Hodge

Max Planck-institutet

F. Walter

Max Planck-institutet

F. Bertoldi

Universität Bonn

A. D. Biggs

European Southern Observatory

C. De Breuck

European Southern Observatory

S. C. Chapman

University of Cambridge Institute of Astronomy

K. E. K. Coppin

McGill University

P. Cox

IRAM Institut de RadioAstronomie Millimetrique

A. L. R. Danielson

University of Durham

H. Dannerbauer

Universitat Wien

R. J. Ivison

Royal Observatory

University of Edinburgh

T. R. Greve

University College London (UCL)

Kirsten Kraiberg Knudsen

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

K. M. Menten

Max Planck-institutet

J. M. Simpson

University of Durham

E. Schinnerer

Max Planck-institutet

J. L. Wardlow

UC Irvine

A. Weiss

Max Planck-institutet

P. van der Werf

Leiden Observatory Research Institute

Monthly Notices of the Royal Astronomical Society

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

Vol. 427 1066-1074


Astronomi, astrofysik och kosmologi


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