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. =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 {mu}m-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 >3{sigma} significance in Karl G. Jansky Very Large Array 1400MHz imaging, of which 35 are also detected at >3{sigma} in new 610MHz Giant Metre-Wave Radio Telescope imaging. Within this sample of radio-detected SMGs, we measure a median radio spectral index {alpha}_{610}_^{1400}^=-0.79+/-0.06, (with inter-quartile range {alpha}=[-1.16,-0.56]) and investigate the far-infrared/radio correlation via the parameter q_IR_, the logarithmic ratio of the rest-frame 8-1000{mu}m flux and monochromatic radio flux. Our median q_IR_=2.56+/-0.05 (inter-quartile range q_IR_=[2.42,2.78]) is higher than that typically seen in single-dish 870{mu}m-selected sources (q_IR_~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 q_IR_ and {alpha} 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 q_IR_ versus {alpha} 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, 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, 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, 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, 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: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table3.dat 103 76 The radio properties of selected ALESS SMGs -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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) 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) 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 8-1000{mu}m infrared flux (S_IR_=L_IR_/4{pi}R^2^) 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 {alpha} 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 -------------------------------------------------------------------------------- Note (1): non-detections are represented by 3{sigma} flux limits. Note (2): q_IR_ = log[(S_IR_/3.75x10^12^W/m^2^)/(S_1.4GHz_/W/m^2^/Hz)] if S_IR_ is the rest-frame 8-1000{mu}m flux and S_1.4GHz_ the rest-frame 1.4GHz flux density. -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 25-Feb-2015