Skip to main content

Research Repository

Advanced Search

An ALMA Survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS Field: The Far-infrared/Radio Correlation for High-redshift Dusty Star-forming Galaxies

Algera, H.S.B.; Smail, I.; Dudzevičiūtė, U.; Swinbank, A.M.; Stach, S.; Hodge, J.A.; Thomson, A.P.; Almaini, O.; Arumugam, V.; Blain, A.W.; Calistro-Rivera, G.; Chapman, S.C.; Chen, C.-C; da Cunha, E.; Farrah, D.; Leslie, S.; Scott, D.; van der Vlugt, D.; Wardlow, J.L.; van der Werf, P.

An ALMA Survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS Field: The Far-infrared/Radio Correlation for High-redshift Dusty Star-forming Galaxies Thumbnail


Authors

H.S.B. Algera

S. Stach

J.A. Hodge

A.P. Thomson

O. Almaini

V. Arumugam

A.W. Blain

G. Calistro-Rivera

S.C. Chapman

C.-C Chen

E. da Cunha

D. Farrah

S. Leslie

D. Scott

D. van der Vlugt

J.L. Wardlow

P. van der Werf



Abstract

We study the radio properties of 706 submillimeter galaxies (SMGs) selected at 870 μm with the Atacama Large Millimeter Array from the SCUBA-2 Cosmology Legacy Survey map of the Ultra Deep Survey field. We detect 273 SMGs at >4σ in deep Karl G. Jansky Very Large Array 1.4 GHz observations, of which a subset of 45 SMGs are additionally detected in 610 MHz Giant Metre-Wave Radio Telescope imaging. We quantify the far-infrared/radio correlation (FIRRC) through parameter q IR, defined as the logarithmic ratio of the far-infrared and radio luminosity, and include the radio-undetected SMGs through a stacking analysis. We determine a median q IR = 2.20 ± 0.03 for the full sample, independent of redshift, which places these z ~ 2.5 dusty star-forming galaxies 0.44 ± 0.04 dex below the local correlation for both normal star-forming galaxies and local ultra-luminous infrared galaxies (ULIRGs). Both the lack of redshift evolution and the offset from the local correlation are likely the result of the different physical conditions in high-redshift starburst galaxies, compared to local star-forming sources. We explain the offset through a combination of strong magnetic fields (B gsim 0.2 mG), high interstellar medium (ISM) densities and additional radio emission generated by secondary cosmic rays. While local ULIRGs are likely to have similar magnetic field strengths, we find that their compactness, in combination with a higher ISM density compared to SMGs, naturally explains why local and high-redshift dusty star-forming galaxies follow a different FIRRC. Overall, our findings paint SMGs as a homogeneous population of galaxies, as illustrated by their tight and nonevolving far-infrared/radio correlation.

Journal Article Type Article
Acceptance Date Sep 9, 2020
Online Publication Date Nov 11, 2020
Publication Date 2020-11
Deposit Date Nov 27, 2020
Publicly Available Date Nov 27, 2020
Journal Astrophysical Journal
Print ISSN 0004-637X
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 903
Issue 2
Article Number 138
DOI https://doi.org/10.3847/1538-4357/abb77b
Public URL https://durham-repository.worktribe.com/output/1250078

Files

Published Journal Article (12.8 Mb)
PDF

Copyright Statement
© 2020. The American Astronomical Society. All rights reserved.






You might also like



Downloadable Citations