Rights statement: This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.3847/1538-4357/abb77b
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - An ALMA Survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS Field
T2 - The Far-infrared/Radio Correlation for High-redshift Dusty Star-forming Galaxies
AU - Algera, H.S.B.
AU - Smail, I.
AU - Dudzevičiūtė, U.
AU - Swinbank, A.M.
AU - Stach, S.
AU - Hodge, J.A.
AU - Thomson, A.P.
AU - Almaini, O.
AU - Arumugam, V.
AU - Blain, A.W.
AU - Calistro-Rivera, G.
AU - Chapman, S.C.
AU - Chen, C.-C.
AU - Da Cunha, E.
AU - Farrah, D.
AU - Leslie, S.
AU - Scott, D.
AU - Van Der Vlugt, D.
AU - Wardlow, J.L.
AU - Van Der Werf, P.
N1 - This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.3847/1538-4357/abb77b
PY - 2020/11/11
Y1 - 2020/11/11
N2 - 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 ⪆ 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. © 2020. The American Astronomical Society. All rights reserved.
AB - 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 ⪆ 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. © 2020. The American Astronomical Society. All rights reserved.
U2 - 10.3847/1538-4357/abb77b
DO - 10.3847/1538-4357/abb77b
M3 - Journal article
VL - 903
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 2
ER -