An ALMA survey of CO in submillimetre galaxies: Companions, triggering, and the environment in blended sources
Artikel i vetenskaplig tidskrift, 2018

We present ALMA observations of the mid-J 12CO emission from six single-dish selected 870-μm sources in the Extended Chandra Deep Field-South and UKIDSS Ultra-Deep Survey fields. These six single-dish submillimetre sources were selected based on previous ALMA continuum observations, which showed that each comprised a blend of emission from two or more individual submillimetre galaxies (SMGs), separated on 5-10 arcsec scales. The six single-dish submillimetre sources targeted correspond to a total of 14 individual SMGs, of which seven have previously measured robust optical/near-infrared spectroscopic redshifts, which were used to tune our ALMA observations.We detect CO(3-2) or CO(4-3) at z = 2.3- 3.7 in 7 of the 14 SMGs, and in addition serendipitously detect line emission from three gas-rich companion galaxies, as well as identify four new 3.3 mm selected continuum sources in the six fields. Joint analysis of ourCOspectroscopy and existing data suggests that 64(±18) per cent of the SMGs in blended submillimetre sources are unlikely to be physically associated. However, three of the SMG fields (50 per cent) contain new, serendipitously detected CO-emitting (but submillimetre-faint) sources at similar redshifts to the 870 μm selected SMGs we targeted. These data suggest that the SMGs inhabit overdense regions, but that these are not sufficiently overdense on ∼100 kpc scales to influence the source blending given the short lifetimes of SMGs. We find that 21 ± 12 per cent of SMGs have spatially distinct and kinematically close companion galaxies (∼8-150 kpc and ≲ 300 km s-1), which may have enhanced their star formation via gravitational interactions.

Galaxies: evolution

Galaxies: ism

Submillimetre: galaxies


J. L. Wardlow

Durham University

J. M. Simpson

Academia Sinica

I. Smail

Durham University

A.M. Swinbank

Durham University

A. Blain

University Of Leicester

W. N. Brandt

Pennsylvania State University

S. C. Chapman

Dalhousie University

C. C. Chen

European Southern Observatory (ESO)

E. A. Cooke

Durham University

H. Dannerbauer

Universidad de la Laguna

Instituto de Astrofísica de Canarias

B. Gullberg

Durham University

J. Hodge

Universiteit Leiden

R. J. Ivison

European Southern Observatory (ESO)

University of Edinburgh

Kirsten Kraiberg Knudsen

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

D. Scott

University of British Columbia (UBC)

A. P. Thomson

Durham University

University of Manchester

A. Weiß


P. van der Werf

Universiteit Leiden

Monthly Notices of the Royal Astronomical Society

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

Vol. 479 3 3879-3891


Meteorologi och atmosfärforskning

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik



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