J/ApJ/768/91 ALMA observations of LESS submm galaxies (Hodge+, 2013)
An ALMA survey of submillimeter galaxies in the Extended Chandra Deep Field
South: source catalog and multiplicity.
Hodge J.A., Karim A., Smail I., Swinbank A.M., Walter F., Biggs A.D.,
Ivison R.J., Weiss A., Alexander D.M., Bertoldi F., Brandt W.N.,
Chapman S.C., Coppin K.E.K., Cox P., Danielson A.L.R., Dannerbauer H.,
De Breuck C., Decarli R., Edge A.C., Greve T.R., Knudsen K.K., Menten K.M.,
Rix H.-W., Schinnerer E., Simpson J.M., Wardlow J.L., van der Werf P.
<Astrophys. J., 768, 91 (2013)>
=2013ApJ...768...91H 2013ApJ...768...91H
ADC_Keywords: Millimetric/submm sources ; Galaxies, IR ; Galaxies, radio ;
Surveys
Keywords: catalogs; galaxies: high-redshift; galaxies: starburst;
submillimeter: galaxies
Abstract:
We present an Atacama Large Millimeter/submillimeter Array (ALMA)
Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS
Submillimeter Survey (LESS). Our 870µm survey with ALMA (ALESS) has
produced maps ∼3x deeper and with a beam area ∼200x smaller than the
original LESS observations, doubling the current number of
interferometrically-observed submillimeter sources. The high
resolution of these maps allows us to resolve sources that were
previously blended and accurately identify the origin of the
submillimeter emission. We discuss the creation of the ALESS
submillimeter galaxy (SMG) catalog, including the main sample of 99
SMGs and a supplementary sample of 32 SMGs. We find that at least 35%
(possibly up to 50%) of the detected LABOCA sources have been resolved
into multiple SMGs, and that the average number of SMGs per LESS
source increases with LESS flux density. Using the (now precisely
known) SMG positions, we empirically test the theoretical expectation
for the uncertainty in the single-dish source positions. We also
compare our catalog to the previously predicted radio/mid-infrared
counterparts, finding that 45% of the ALESS SMGs were missed by this
method. Our ∼1.6" resolution allows us to measure a size of ∼9kpcx5kpc
for the rest-frame ∼300µm emission region in one resolved SMG,
implying a star formation rate surface density of 80M☉/yr/kpc2,
and we constrain the emission regions in the remaining SMGs to be
<10kpc. As the first statistically reliable survey of SMGs, this will
provide the basis for an unbiased multiwavelength study of SMG
properties.
Description:
The ALMA observations were taken between 2011 October 18 and 2011
November 3 as part of Cycle 0 Project #2011.1.00294.S. The targets
were the 126 submillimeter sources originally detected in LABOCA ECDFS
Submillimeter Survey (LESS; Weiss et al. 2009, J/ApJ/707/1201), which
had an angular resolution of ∼19" FWHM and an rms sensitivity of
σ870um=1.2mJy/beam.
We observed the LESS sources with ALMA's Band 7 centered at 344GHz
(870um) -the same frequency as LESS for direct comparison of the
measured flux densities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 126 ALESS observations by LESS field
table3.dat 87 99 ALESS MAIN sample sources by LESS field
table4.dat 89 32 ALESS supplementary sample
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See also:
J/ApJS/205/13 : VLA 1.4GHz survey of ECDF-S (DR2) (Miller+, 2013)
J/MNRAS/415/1479 : LESS photometric redshift survey (Wardlow+, 2011)
J/MNRAS/413/2314 : Radio and MIR counterpart of submm galaxies (Biggs+, 2011)
J/MNRAS/405/2260 : GOODS-S field AzTEC/ASTE Deep 1.1mm imaging (Scott+, 2010)
J/ApJ/707/1201 : LABOCA ECDFS Submillimeter Survey (LESS) (Weiss+, 2009)
J/other/Nat/458.737 : BLAST sources at 250, 350 and 500um (Devlin+, 2009)
J/ApJS/179/114 : VLA 1.4GHz survey of E-CDF-S (Miller+, 2008)
J/ApJS/179/95 : VLA survey of CDF-S. II. (Mainieri+, 2008)
J/ApJS/179/19 : CDFS survey: 2 Ms source catalogs (Luo+, 2008)
J/MNRAS/380/199 : SCUBA Half-Degree Extragalactic Survey. III (Ivison+, 2007)
J/MNRAS/372/1621 : SCUBA Half-Degree Extragalactic Survey. II (Coppin+, 2006)
J/MNRAS/370/1057 : Blank-field SCUBA surveys (Scott+ 2006)
J/ApJ/622/772 : Redshift survey of submillimeter galaxies (Chapman+, 2005)
J/ApJS/161/21 : Extended Chandra Deep Field-South survey (Lehmer+, 2005)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [LESS]
6- 8 I3 --- LESS [1/126] LESS identification number
( in Simbad)
11 I1 h RAh [3] Hour of Right Ascension (J2000)
13- 14 I2 min RAm [31/33] Minute of Right Ascension (J2000)
16- 20 F5.2 s RAs Second of Right Ascension (J2000)
22 A1 --- DE- [-] Sign of the Declination (J2000)
23- 24 I2 deg DEd [27/28] Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcminute of Declination (J2000)
29- 32 F4.1 arcsec DEs Arcsecond of Declination (J2000)
34- 37 F4.1 mJy S870 [3.5/14.5] 870um flux density measured with
LABOCA; in mJy/beam
39- 41 F3.1 mJy e_S870 Error on S; mJy/beam
43- 46 F4.1 --- SNR [3.7/12.5] LABOCA signal-to-noise ratio
48- 51 F4.2 mJy rms [0.3/2.5]? RMS in the ALMA map at phase center
53- 56 F4.2 arcsec Bmaj ? Major axis of ALMA's synthesized beam
58- 61 F4.2 arcsec Bmin ? Minor axis of ALMA's synthesized beam
63- 65 A3 --- SB Scheduling block (1)
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Note (1): Scheduling block (SB) as in Table 1:
------------------------------------------------------------------------------
SB Date Antennas LESS Notes
12m only fields
------------------------------------------------------------------------------
SB1 2011/Oct/18 15 16 a
SB2 2011/Oct/18 15 15 b
SB3 2011/Oct/20 15 16
SB4 2011/Oct/20 15 15 a
SB5 2011/Oct/20 15 16 b
SB6 2011/Oct/21 13 16 Flux calibrator unusable (20° elevation);
used flux scale solutions from SB5
SB7 2011/Oct/21 12 13 b but (20°-30°)
SB8 2011/Nov/03 14 15
------------------------------------------------------------------------------
Notes:
a = No flux calibrator; used flux scale solutions from SB3
b = Science fields observed at low elevation (20°-40°)
------------------------------------------------------------------------------
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Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [LESS]
6- 8 I3 --- LESS [1/126] LESS identification number
10- 14 A5 --- --- [ALESS]
16- 21 A6 --- ALESS ALESS source identifier (see the
"Nomenclature Notes" section below)
24 I1 h RAh [3] Hour of Right Ascension (J2000)
26- 27 I2 min RAm [31/33] Minute of Right Ascension (J2000)
29- 33 F5.2 s RAs Second of Right Ascension (J2000)
35 A1 --- DE- [-] Sign of the Declination (J2000)
36- 37 I2 deg DEd [27/28] Degree of Declination (J2000)
39- 40 I2 arcmin DEm Arcminute of Declination (J2000)
42- 45 F4.1 arcsec DEs Arcsecond of Declination (J2000)
47- 50 F4.2 arcsec e_RAs [0.02/0.3] Uncertainty in RAs
52- 55 F4.2 arcsec e_DEs [0.02/0.4] Uncertainty in Declination
57- 59 F3.1 mJy Spk [1/9] ALMA peak flux density at 870um
61- 63 F3.1 mJy e_Spk Uncertainty in Spk
65- 67 F3.1 mJy Sint [1.2/10] ALMA integrated flux density at 870um
69- 71 F3.1 mJy e_Sint Uncertainty in Sint
73- 76 F4.1 --- SNR [3.5/25] Peak signal-to-noise ratio
78- 81 F4.1 mJy Sbest [1.3/12] Best flux density estimate (1)
83- 85 F3.1 mJy e_Sbest Uncertainty in Sbest
87 A1 --- B11 [rt] robust or tentative counterpart in B11 (2)
89 A1 --- Set [2/3]? Supplementary sample selection flag
(2=should be used with care) (3)
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Note (1): Primary-beam corrected.
Note (2): B11 = Biggs et al. 2011 (J/MNRAS/413/2314;
<[BII2011] MIPS JHHMMSS.ssss+DDMMSS.sss> in Simbad).
See Section 5.5 for further details.
Note (3): Indicates why the sub-mm galaxy (SMG) was selected as supplementary
(see Section 4.1 for further details):
2 = The rms of the ALMA map is less than 0.6mJy/beam; the ratio of the major
and minor axes of the synthesized beam is less than two; the SMG lies
outside the ALMA primary beam FWHM; and the S/N of the SMG is greater
than four. SMGs of good-quality but lying outside the primary beam FWHM.
3 = The rms of the ALMA map is greater than 0.6mJy/beam OR the ratio of the
major and minor axes of the synthesized beam is greater than two; the SMG
lies inside the ALMA primary beam FWHM; and the S/N of the SMG is greater
than four. SMGs which come from maps of just slightly worse quality than
the "good quality" maps are likely reliable, while those from the noisiest
maps (Figure 9) should be used with extreme care, as even SMGs near the
phase center may be spurious.
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Nomenclature Notes:
Tables 3-4: submillimeter galaxies (SMGs) are:
<[HKS2013] ALESS NNN.NN> = in Simbad.
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 26-Nov-2014