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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: radio properties and the far-infrared/radio correlation
AU - Thomson, A. P.
AU - Ivison, R. J.
AU - Simpson, J. M.
AU - Swinbank, A. M.
AU - Smail, Ian
AU - Arumugam, V.
AU - Alexander, D. M.
AU - Beelen, A.
AU - Brandt, W. N.
AU - Chandra, I.
AU - Dannerbauer, H.
AU - Greve, T. R.
AU - Hodge, J. A.
AU - Ibar, E.
AU - Karim, A.
AU - Murphy, E. J.
AU - Schinnerer, E.
AU - Sirothia, S.
AU - Walter, F.
AU - Wardlow, J. L.
AU - van der Werf, P.
PY - 2014/7/1
Y1 - 2014/7/1
N2 - We present a study of the radio properties of 870 μm-selected submillimetre galaxies (SMGs), observed at high resolution with Atacama Large Millimeter Array (ALMA) in the Extended Chandra Deep Field South. From our initial sample of 76 ALMA SMGs, we detect 52 SMGs at >3σ significance in Karl G. Jansky Very Large Array 1400 MHz imaging, of which 35 are also detected at >3σ in new 610 MHz Giant Metre-Wave Radio Telescope imaging. Within this sample of radio-detected SMGs, we measure a median radio spectral index α _{610}^{1400} = -0.79 ± 0.06, (with inter-quartile range α = [-1.16, -0.56]) and investigate the far-infrared/radio correlation via the parameter qIR, the logarithmic ratio of the rest-frame 8-1000 μm flux and monochromatic radio flux. Our median qIR = 2.56 ± 0.05 (inter-quartile range qIR = [2.42, 2.78]) is higher than that typically seen in single-dish 870 μm-selected sources (qIR ˜ 2.4), which may reflect the fact that our ALMA-based study is not biased to radio-bright counterparts, as previous samples were. Finally, we search for evidence that qIR and α evolve with age in a codependent manner, as predicted by starburst models: the data populate the predicted region of parameter space, with the stellar mass tending to increase along tracks of qIR versus α in the direction expected, providing the first observational evidence in support of these models.
AB - We present a study of the radio properties of 870 μm-selected submillimetre galaxies (SMGs), observed at high resolution with Atacama Large Millimeter Array (ALMA) in the Extended Chandra Deep Field South. From our initial sample of 76 ALMA SMGs, we detect 52 SMGs at >3σ significance in Karl G. Jansky Very Large Array 1400 MHz imaging, of which 35 are also detected at >3σ in new 610 MHz Giant Metre-Wave Radio Telescope imaging. Within this sample of radio-detected SMGs, we measure a median radio spectral index α _{610}^{1400} = -0.79 ± 0.06, (with inter-quartile range α = [-1.16, -0.56]) and investigate the far-infrared/radio correlation via the parameter qIR, the logarithmic ratio of the rest-frame 8-1000 μm flux and monochromatic radio flux. Our median qIR = 2.56 ± 0.05 (inter-quartile range qIR = [2.42, 2.78]) is higher than that typically seen in single-dish 870 μm-selected sources (qIR ˜ 2.4), which may reflect the fact that our ALMA-based study is not biased to radio-bright counterparts, as previous samples were. Finally, we search for evidence that qIR and α evolve with age in a codependent manner, as predicted by starburst models: the data populate the predicted region of parameter space, with the stellar mass tending to increase along tracks of qIR versus α in the direction expected, providing the first observational evidence in support of these models.
KW - galaxies: evolution
KW - galaxies: high-redshift
KW - galaxies: starburst
U2 - 10.1093/mnras/stu839
DO - 10.1093/mnras/stu839
M3 - Journal article
VL - 442
SP - 577
EP - 588
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -