J/MNRAS/442/577 Selected ALESS submm galaxies radio properties (Thomson+, 2014)
An ALMA survey of submillimetre galaxies in the Extended Chandra Deep
Field-South: radio properties and the far-infrared/radio correlation.
Thomson A.P., Ivison R.J., Simpson J.M., Swinbank A.M., Smail I.,
Arumugam V., Alexander D.M., Beelen A., Brandt W.N., Chandra I.,
Dannerbauer H., Greve T.R., Hodge J.A., Ibar E., Karim A., Murphy E.J.,
Schinnerer E., Sirothia S., Walter F., Wardlow J.L., van der Werf P.
<Mon. Not. R. Astron. Soc., 442, 577-588 (2014)>
=2014MNRAS.442..577T 2014MNRAS.442..577T
ADC_Keywords: Galaxy catalogs ; Millimetric/submm sources ; Radio sources
Keywords: galaxies: evolution - galaxies: high-redshift - galaxies: starburst
Abstract:
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
1400MHz imaging, of which 35 are also detected at >3σ in new
610MHz 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 8-1000µm 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 870µm-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.
Description:
ALMA 870-um observations were presented in Hodge et al.
(2013ApJ...768...91H 2013ApJ...768...91H, Cat. J/ApJ/768/91), in which detailed
descriptions of the data reduction and imaging are given. Briefly, we
observed 122 of the 126 known submillimetre sources from the LABOCA
ECDFS (LESS) survey of Weiss et al. (2009ApJ...707.1201W 2009ApJ...707.1201W, Cat.
J/ApJ/707/1201) with ALMA's Band 7 receivers (870-um) in Cycle 0,
between 2011 October 18 and November 3.
GMRT observations of the ECDFS were obtained between 2009 October and
2010 February.
We rely on data from the VLA 1.4-GHz Survey of the ECDFS DR2 (Miller
et al., 2013ApJS..205...13M 2013ApJS..205...13M, Cat. J/ApJS/205/13), a re-reduction of
the same 250 h of A-configuration data taken from 2007 June to
September as were used by Biggs et al. (2011MNRAS.413.2314B 2011MNRAS.413.2314B, Cat.
J/MNRAS/413/2314) to produce the first deep radio catalogue of ECDFS.
In our analysis, we exploit previously measured photometric redshifts
and FIR luminosities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 103 76 The radio properties of selected ALESS SMGs
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See also:
J/ApJ/707/1201 : LABOCA ECDFS Submillimeter Survey (LESS) (Weiss+, 2009)
J/MNRAS/413/2314 : Submm galaxies radio and mid-IR counterpart (Biggs+, 2011)
J/ApJS/205/13 : VLA 1.4GHz survey of ECDF-S (DR2) (Miller+, 2013)
J/ApJ/768/91 : ALMA observations of LESS submm galaxies (Hodge+, 2013)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [ALESS]
7- 12 A6 --- ALESS ALESS ID (NNN.NN)
14- 20 F7.4 deg RAdeg Right ascension (J2000)
23- 30 F8.4 deg DEdeg Declination (J2000)
33- 36 F4.2 --- zph [0.4/6.6] Photometric redshift from
Simpson et al. (2014ApJ...788..125S 2014ApJ...788..125S)
38- 41 F4.2 --- b_zph Lower value of zph confidence interval
43- 46 F4.2 --- B_zph Upper value of zph confidence interval
48- 50 F3.1 mJy S870 [1.3/9] ALMA flux density at 870um from
Swinbank et al. (2014MNRAS.438.1267S 2014MNRAS.438.1267S)
52- 54 F3.1 mJy e_S870 [0.3/0.9] rms uncertainty on S870
56 A1 --- l_S1.4G [<] Limit flag on S1.4 (1)
57- 59 I3 uJy S1.4G [23/273] VLA flux density at 1.4GHz
61- 62 I2 uJy e_S1.4G [6/11] rms uncertainty on S1.4G
64 A1 --- l_S610M [<] Limit flag on S610M (1)
65- 67 I3 uJy S610M [41/533] GMRT flux density at 610MHz
69- 70 I2 uJy e_S610M [13/50] rms uncertainty on S610M
72- 75 F4.2 fW/m2 SIR [0.03/1.13] Rest-frame 8-1000µm infrared
flux (SIR=LIR/4πR2)
77- 80 F4.2 fW/m2 e_SIR [0/1.71] rms uncertainty on SIR
82 A1 --- l_alpha [>] Limit flag on alpha
83- 87 F5.2 --- alpha [-1.8/0.6]?=- Spectral index α
between 610MHz and 1.4GHz
89- 92 F4.2 --- e_alpha [0.03/0.34]?=- rms uncertainty on alpha
94 A1 --- l_qIR [<] Limit flag on qIR
95- 98 F4.2 [-] qIR [0.28/3.33] Infrared/radio flux ratio (2)
100-103 F4.2 [-] e_qIR [0.01/0.94]?=- rms uncertainty on qIR
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Note (1): non-detections are represented by 3σ flux limits.
Note (2): qIR = log[(SIR/3.75x1012W/m2)/(S1.4GHz/W/m2/Hz)]
if SIR is the rest-frame 8-1000µm flux and
S1.4GHz the rest-frame 1.4GHz flux density.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Feb-2015