J/ApJ/839/58 ALMA submm galaxies multi-wavelength data (Simpson+, 2017)
The SCUBA-2 cosmology legacy Survey: multi-wavelength properties of
ALMA-identified submillimeter galaxies in UKIDSS UDS.
Simpson J.M., Smail I., Swinbank A.M., Ivison R.J., Dunlop J.S.,
Geach J.E., Almaini O., Arumugam V., Bremer M.N., Chen C.-C., Conselice C.,
Coppin K.E.K., Farrah D., Ibar E., Hartley W.G., Ma C.J., Michalowski M.J.,
Scott D., Spaans M., Thomson A.P., van der Werf P.P.
<Astrophys. J., 839, 58 (2017)>
=2017ApJ...839...58S 2017ApJ...839...58S
ADC_Keywords: Galaxies, photometry ; Millimetric/submm sources ; Radio sources ;
Photometry, infrared
Keywords: galaxies: evolution ; galaxies: high-redshift ; galaxies: starburst ;
submillimeter: galaxies
Abstract:
We present a multi-wavelength analysis of 52 submillimeter galaxies
(SMGs), identified using ALMA 870µm continuum imaging in a pilot
program to precisely locate bright SCUBA-2-selected submillimeter
sources in the UKIDSS Ultra Deep Survey (UDS) field. Using the
available deep (especially near-infrared) panoramic imaging of the UDS
field at optical-to-radio wavelengths we characterize key properties
of the SMG population. The median photometric redshift of the bright
ALMA/SCUBA-2 UDS (AS2UDS) SMGs that are detected in a sufficient
number of wavebands to derive a robust photometric redshift is
z=2.65±0.13. However, similar to previous studies, 27% of the SMGs
are too faint at optical-to-near-infrared wavelengths to derive a
reliable photometric redshift. Assuming that these SMGs lie at z≳3
raises the median redshift of the full sample to z=2.9±0.2. A subset
of 23 unlensed, bright AS2UDS SMGs have sizes measured from resolved
imaging of their rest- frame far-infrared emission. We show that the
extent and luminosity of the far-infrared emission are consistent with
the dust emission arising from regions that are, on average, optically
thick at a wavelength of λ0≥75µm (1σ dispersion of
55-90µm). Using the dust masses derived from our optically thick
spectral energy distribution models, we determine that these galaxies
have a median hydrogen column density of
NH=9.8-0.7+1.4x1023cm-2, or a corresponding median V-band
obscuration of Av=540-40+80mag, averaged along the line of sight
to the source of their rest-frame ∼200µm emission. We discuss the
implications of this extreme attenuation by dust for the
multi-wavelength study of dusty starbursts and reddening-sensitive
tracers of star formation.
Description:
In previous work, we presented the source catalog, number counts, and
far-infrared morphologies of the 52 SMGs that were detected in 30 ALMA
maps (see Simpson+ 2015ApJ...799...81S 2015ApJ...799...81S, 2015ApJ...807..128S 2015ApJ...807..128S).
The UKIDSS observations of the ∼0.8deg2 UDS comprise four Wide-Field
Camera (WFCAM) pointings in the J-, H-, and K-bands. In this paper, we
use the images and catalogs released as part of the UKIDSS data
release 8 (DR8). The DR8 release contains data taken between 2005 and
2010, and the final J-, H-, and K-band mosaics have a median 5σ
depth (2" apertures) of J=24.9, H=24.2, and K=24.6, respectively.
Deep observations of the UDS have also been taken in the U-band with
Megacam at the Canada-France-Hawaii Telescope (CFHT) and in the B, V,
R, i', and z' bands with Suprime-cam at the Subaru telescope.
Furthermore, deep Spitzer data, obtained as part of the SpUDS program
(PI: J. Dunlop) provides imaging reaching a 5σ depth of
m3.6=24.2 and m4.5=24.0 at 3.6um and 4.5um, respectively.
The UDS field was observed at 250, 350, and 500um with the Spectral
and Photometric Imaging Receiver (SPIRE) onboard the Herschel Space
Observatory as part of the Herschel Multi-tiered Extragalactic Survey
(HerMES).
The UDS field was observed by the VLA at 1.4GHz as part of the project
UDS20 (V. Arumugam et al. 2017, in preparation). A total of 14
pointings were used to mosaic an area of ∼1.3deg2 centered on the
UDS field.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 100 52 Observed properties of ALMA submillimeter galaxies
(SMGs)
table2.dat 115 52 Physical properties
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
VIII/95 : Herschel Multi-tiered Extragalactic Survey (Oliver+, 2012)
J/ApJ/622/772 : Redshift survey of submillimeter galaxies (Chapman+, 2005)
J/MNRAS/372/1621 : SCUBA Half-Degree Extragalactic Survey. II (Coppin+, 2006)
J/MNRAS/380/199 : SCUBA Half-Degree Extragalactic Survey. III (Ivison+, 2007)
J/ApJS/176/1 : Subaru/XMM-Newton deep survey (SXDS). II. (Furusawa+, 2008)
J/MNRAS/385/2225 : AzTEC millimetre survey of COSMOS field (Scott+, 2008)
J/ApJ/699/1610 : Spitzer survey of submillimeter galaxies (Hainline+, 2009)
J/MNRAS/413/2314 : Radio and MIR counterpart of submm galaxies (Biggs+, 2011)
J/ApJ/768/91 : ALMA observations of LESS submm galaxies (Hodge+, 2013)
J/MNRAS/444/117 : Luminous (sub-)millimetre galaxies (Koprowski+, 2014)
J/MNRAS/441/1017 : Multiwavelength photometry of 34 galaxies (Rowlands+, 2014)
J/ApJ/788/125 : An ALMA survey of ECDFS submm galaxies (Simpson+, 2014)
J/ApJ/799/10 : Arp 220 6 and 33GHz images (Barcos-Munoz+, 2015)
J/ApJ/806/110 : ALESS survey: SMGs in the ECDF-S data (da Cunha+, 2015)
J/A+A/591/A136 : Galaxies & QSOs FIR size & surface brightness (Lutz+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Identifier
10 A1 --- f_ID [a] a: identified as a potentially lensed SMG
12- 13 I2 h RAh [2] Hour of Right Ascension (J2000)
15- 16 I2 min RAm [16/19] Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- [-] Sign of the Declination (J2000)
25- 26 I2 deg DEd [4/5] Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 34 F4.1 arcsec DEs Arcsecond of Declination (J2000)
36 A1 --- l_Kmag Limit flag on Kmag
38- 42 F5.2 mag Kmag [21/25.4]? Apparent K band total AB magnitude
44- 47 F4.2 mag e_Kmag [0.01/2]? Uncertainty in Kmag
49 A1 --- l_S250 Limit flag on S250
51- 54 F4.1 mJy S250 [7/86] Herschel/SPIRE 250um band flux density
56- 58 F3.1 mJy e_S250 [2/8]? Uncertainty in S250
60 A1 --- l_S350 Limit flag on S350
62- 65 F4.1 mJy S350 [9/65] Herschel/SPIRE 350um band flux density
67- 69 F3.1 mJy e_S350 [3/7]? Uncertainty in S350
71 A1 --- l_S500 Limit flag on S500
73- 76 F4.1 mJy S500 [12/38] Herschel/SPIRE 500um band flux density
78- 80 F3.1 mJy e_S500 [3/7]? Uncertainty in S500
82- 85 F4.1 mJy S870 [1/13] ALMA 870 micron band flux density
87- 89 F3.1 mJy e_S870 [0.4/1] Uncertainty in S870
91- 95 F5.1 uJy S1.4 [39/783]? VLA 1.4GHz band flux density
97-100 F4.1 uJy e_S1.4 [7/45]? Uncertainty in S1.4
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Identifier
10- 10 A1 --- f_ID [a] a: identified as a potentially lensed
SMG
12- 15 F4.2 --- zphot [0.6/5.1]? Photometric redshift
17- 20 F4.2 --- E_zphot [0.04/1.6]? Upper uncertainty in zphot
22- 25 F4.2 --- e_zphot [0.05/2.1]? Lower uncertainty in zphot
27- 31 F5.2 10+12Lsun LThin [1.2/12]? Far-IR luminosity
assuming an optically-thin SED
33- 36 F4.2 10+12Lsun E_LThin [0/1.5]? Upper uncertainty in LThin (1)
38- 42 F5.2 10+12Lsun e_LThin [0.05/11]? Lower uncertainty in LThin (1)
44 A1 --- l_TThin Limit flag on TThin
46- 49 F4.1 K TThin [15/55]? Temperature
assuming an optically-thin SED
51- 53 F3.1 K E_TThin [0.6/6]? Upper uncertainty in TThin
55- 57 F3.1 K e_TThin [1.4/5]? Lower uncertainty in TThin
59 A1 --- l_FWHM Limit flag on FWHM
61- 64 F4.2 arcsec FWHM [0.1/0.7]? Intrinsic source size (2)
66- 69 F4.2 arcsec e_FWHM [0.02/0.07]? Uncertainty in FWHM
71 A1 --- l_TB Limit flag on TB
73- 76 F4.1 K TB [12.6/55.5]? Average dust brightness
temperature (3)
78- 82 F5.2 10+12Lsun LThick [1.5/11.2]? Far-IR luminosity (4)
84- 87 F4.2 10+12Lsun E_LThick [0.3/2.1]? Upper uncertainty in LThick
89- 92 F4.2 10+12Lsun e_LThick [0.2/2]? Lower uncertainty in LThick
94- 97 F4.1 K TThick [27/46]? Temperature (4)
99-101 F3.1 K E_TThick [1/5]? Uncertainty in TThick
103-105 F3.1 K e_TThick [1/4]? Uncertainty in TThick
107-109 I3 um lambda [32/125]? Wavelength (4)
111-112 I2 um E_lambda [4/20]? Upper uncertainty in lambda
114-115 I2 um e_lambda [3/16]? Lower uncertainty in lambda
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Note (1): The full range of plausible values are given for sources that
are only detected in the far-infrared at 870um.
Note (2): Corrected for synthesized beam, at observed 870um (see
Simpson+ 2015ApJ...807..128S 2015ApJ...807..128S
Note (3): Contained within the half-light radius of the
observed 870 micron emission.
Note (4): Assuming an optically-thick SED, and using observed size of the
870um emission as a Gaussian prior in the FIR SED fitting.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 21-Nov-2017