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Early Science with the Large Millimeter Telescope: observations of dust continuum and CO emission lines of cluster-lensed submillimetre galaxies at z=2.0-4.7

Zavala, J.A.; Yun, M.S.; Aretxaga, I.; Hughes, D.H.; Wilson, G.W.; Geach, J.E.; Egami, E.; Gurwell, M.A.; Wilner, D.J.; Smail, I.; Blain, A.W.; Chapman, S.C.; Coppin, K.E.K.; Dessauges-Zavadsky, M.; Edge, A.C.; Montaña, A.; Nakajima, K.; Rawle, T.D.; Sánchez-Argüelles, D.; Swinbank, A.M.; Webb, T.M.A.; Zeballos, M.

Early Science with the Large Millimeter Telescope: observations of dust continuum and CO emission lines of cluster-lensed submillimetre galaxies at z=2.0-4.7 Thumbnail


J.A. Zavala

M.S. Yun

I. Aretxaga

D.H. Hughes

G.W. Wilson

J.E. Geach

E. Egami

M.A. Gurwell

D.J. Wilner

A.W. Blain

S.C. Chapman

K.E.K. Coppin

M. Dessauges-Zavadsky

A. Montaña

K. Nakajima

T.D. Rawle

D. Sánchez-Argüelles

T.M.A. Webb

M. Zeballos


We present Early Science observations with the Large Millimeter Telescope, AzTEC 1.1 mm continuum images and wide bandwidth spectra (73–111 GHz) acquired with the Redshift Search Receiver, towards four bright lensed submillimetre galaxies identified through the Herschel Lensing Survey-snapshot and the Submillimetre Common-User Bolometer Array-2 Cluster Snapshot Survey. This pilot project studies the star formation history and the physical properties of the molecular gas and dust content of the highest redshift galaxies identified through the benefits of gravitational magnification. We robustly detect dust continuum emission for the full sample and CO emission lines for three of the targets. We find that one source shows spectroscopic multiplicity and is a blend of three galaxies at different redshifts (z = 2.040, 3.252, and 4.680), reminiscent of previous high-resolution imaging follow-up of unlensed submillimetre galaxies, but with a completely different search method, that confirm recent theoretical predictions of physically unassociated blended galaxies. Identifying the detected lines as 12CO (Jup = 2–5) we derive spectroscopic redshifts, molecular gas masses, and dust masses from the continuum emission. The mean H2 gas mass of the full sample is (2.0 ± 0.2) × 1011 M⊙/μ, and the mean dust mass is (2.0 ± 0.2) × 109 M⊙/μ, where μ ≈ 2–5 is the expected lens amplification. Using these independent estimations we infer a gas-to-dust ratio of δGDR ≈ 55–75, in agreement with other measurements of submillimetre galaxies. Our magnified high-luminosity galaxies fall on the same locus as other high-redshift submillimetre galaxies, extending the L′CO–LFIR correlation observed for local luminous and ultraluminous infrared galaxies to higher far-infrared and CO luminosities.

Journal Article Type Article
Publication Date Sep 1, 2015
Deposit Date Oct 28, 2015
Publicly Available Date Nov 4, 2015
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 452
Issue 2
Pages 1140-1151
Keywords Galaxies: evolution, Galaxies: high-redshift, Galaxies: ISM, Cosmology: observations, Submillimetre: galaxies
Public URL
Publisher URL


Published Journal Article (1.2 Mb)

Copyright Statement
This article has been published in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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