J/MNRAS/487/4648 ALMA survey of the SCUBA-2 UKIDSS/UDS field (Stach+, 2019)
An ALMA survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS field:
source catalogue and properties.
Stach S.M., Dudzeviciute U., Smail I., Swinbank A.M., Geach J.E.,
Simpson J.M., An F.X., Almaini O., Arumugam V., Blain A.W., Chapman S.C.,
Chen C.-C., Conselice C.J., Cooke E.A., Coppin K.E.K., da Cunha E.,
Dunlop J.S., Farrah D., Gullberg B., Hodge J.A., Ivison R.J.,
Kocevski D.D., Michalowski M.J., Miyaji T., Scott D., Thomson A.P.,
Wardlow J.L., Weiss A., van der Werf P.
<Mon. Not. R. Astron. Soc., 487, 4648-4668 (2019)>
=2019MNRAS.487.4648S 2019MNRAS.487.4648S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Millimetric/submm sources ; Magnitudes
Keywords: galaxies: high-redshift - galaxies: starburst -
submillimetre: galaxies
Abstract:
We present the catalogue and basic properties of sources in AS2UDS, an
870-µm continuum survey with the Atacama Large
Millimetre/sub-millimetre Array (ALMA) of 716 single-dish
sub-millimetre sources detected in the UKIDSS/UDS field by the SCUBA-2
Cosmology Legacy Survey. In our sensitive ALMA follow-up observations,
we detect 708 sub-millimetre galaxies (SMGs) at >4.3σ
significance across the ∼1°-diameter field. We combine our precise
ALMA positions with the extensive multiwavelength coverage in the UDS
field which yields spectral energy distributions for our SMGs and a
median redshift of zphot=2.61±0.09. This large sample reveals a
statistically significant trend of increasing sub-millimetre flux with
redshift suggestive of galaxy downsizing. 101 ALMA maps do not show
a>4.3σ SMG, but we demonstrate from stacking Herschel SPIRE
observations at these positions, that the vast majority of these blank
maps correspond to real single-dish sub-millimetre sources. We further
show that these blank maps contain an excess of galaxies at
zphot=1.5-4 compared to random fields, similar to the redshift range
of the ALMA-detected SMGs. In addition, we combine X-ray and
mid-infrared active galaxy nuclei activity (AGN) indicators to yield a
likely range for the AGN fraction of 8-28 per cent in our sample.
Finally, we compare the redshifts of this population of high-redshift,
strongly star-forming galaxies with the inferred formation redshifts
of massive, passive galaxies being found out to z∼2, finding
reasonable agreement - in support of an evolutionary connection
between these two classes of massive galaxy.
Description:
AS2UDS is a high-resolution, sub-millimetre interferometric follow-up
survey of the SCUBA-2 850µm sources selected from the S2CLS map of
the UDS field. The parent single-dish survey covers an area of
0.96deg2, with noise levels below 1.3mJy and a median depth of
σ850=0.88mJy/beam with 80 per cent of sources identified in
regions of the map with σ850=0.86-1.02mJy/beam (Geach et al.
2017MNRAS.465.1789G 2017MNRAS.465.1789G, J/MNRAS/465/1789). Across four ALMA cycles (1, 3,
4, and 5) we observed all 716 >4σ sources from the SCUBA-2 S2CLS
map, corresponding to observed flux densities S850≥3.4mJy. We
identified 708 >4.3σ sources which account for the majority of
the flux detected in the parent SCUBA-2 map.
In Cycle 1 (Project ID: 2012.1.00090.S), 30 of the brightest sources
from an early version of the SCUBA-2 UDS map (data taken before 2013
February) were observed in ALMA Band 7 (Simpson et al.
2015ApJ...799...81S 2015ApJ...799...81S, 2015ApJ...807..128S 2015ApJ...807..128S, 2017ApJ...839...58S 2017ApJ...839...58S, Cat.
J/ApJ/839/58). This early version of the SCUBA-2 map had a depth of
only σ850∼2.0mJy/beam and subsequent integration time in the
S2CLS survey scattered three of these sources below our final sample
selection criteria (>4σ), leaving 27 of these original
single-dish detected sources in our final sample. The remaining 689
single-dish sources in the final S2CLS catalogue were observed across
ALMA cycles 3 and 4 (Project ID: 2015.1.01528.S and 2016.1.00434.S,
respectively). To cross-calibrate the data, a fraction of these
sources were observed twice, once in Cycle 3 and 4. In addition, in
Cycle 5 ten of the brightest SCUBA-2 sources which returned 'blank'
maps from the Cycle 3 and 4 ALMA observations were re-observed at
greater depth (Project ID: 2017.1.01492.S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 136 708 The AS2UDS Catalogue
tablea1.dat 200 708 AS2UDS multiwavelength photometry
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.1 --- ID ALMA identifier NNNN.N (G1)
8- 34 A27 --- Name ALMA source name
(AS2UDS JHHMMSS.ss-DDMMSS.ss)
36- 39 A4 --- MS Identifier for which measurement set the
ALMA pointing belongs to and thus which
Cycle it was observed
41- 54 F14.11 deg RAfdeg Right ascension (J2000) of the ALMA phase
centre (1)
56- 70 F15.12 deg DEfdeg Declination (J2000) of the ALMA phase
centre (1)
72- 76 F5.3 mJy/beam RMS Sigma-clipped rms of the pixels within the
primary beams before primary beam
correction
78- 83 F6.4 arcsec Beammax Restoring beam maximum size in the
uv-tapered detection maps
85- 90 F6.4 arcsec Beammin Restoring beam minimum size in the
uv-tapered detection maps
92- 99 F8.5 deg RAdeg Right ascension (J2000) of the ALMA
detection centroid of the source from
SEXTRACTOR from the uv-tapered detection
maps
101-108 F8.5 deg DEdeg Declination (J2000) of the ALMA detection
centroid of the source from SEXTRACTOR
from the uv-tapered detection maps
110-113 F4.1 --- SNR Signal to noise ratio for a 0.5arcsec
diameter aperture
115-118 F4.2 --- PB Primary beam correction factor
120-123 F4.1 mJy/beam Flux 1.0arcsec diameter aperture flux of the
galaxy with the primary beam, aperture,
and flux boosting corrections applied
125-127 F3.1 mJy/beam e_Flux Error on Flux
129-132 F4.1 mJy/beam S2CLS Observed 850µm flux from Geach et al.
(2017MNRAS.465.1789G 2017MNRAS.465.1789G,
Cat. J/MNRAS/465/1789)
134-136 F3.1 mJy/beam e_S2CLS Error on S2CLS
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Note (1): The location of the ALMA phase centres are the locations of the
parent S2CLS source (except for Cycle 1 targets)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.1 --- ID ALMA identifier NNNN.N (G1)
8- 25 F18.15 mag Vmag ? V-band corrected 2arcsec-aperture AB
magnitudes from the UKIDSS UDS survey
(Almaini et al. in preparation)
27- 47 F21.19 mag e_Vmag ? Error on Vmag
49- 66 F18.15 mag Kmag ? K-band corrected 2arcsec-aperture AB
magnitudes from the UKIDSS UDS survey
(Almaini et al. in preparation)
68- 88 F21.19 mag e_Kmag ? Error on Kmag
90- 94 A5 --- f_ID ? Flag on ID (1)
96-115 F20.15 uJy VLA1.4 ? VLA 1.4GHz flux from the UDS20 survey
(Arumugan et al. in preparation)
117-135 F19.16 uJy e_VLA1.4 ? Error on VLA1.4
137-149 F13.10 mag 3.6mag ? 3.6um IRAC magnitude (2)
151-163 F13.10 mag 4.5mag ? 4.5um IRAC magnitude (2)
165-177 F13.10 mag 5.8mag ? 5.8um IRAC magnitude (2)
179-191 F13.10 mag 8.0mag ? 8.0um IRAC magnitude (2)
193-200 A8 --- XUDSID ? X-UDS identifier (Kocevski et al.
2018ApJS..236...48K 2018ApJS..236...48K, Cat. J/ApJS/236/48)
(xuds_NNN) for the 23 matches with our SMGs
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Note (1): Flag as follows:
true = unmasked, 'good', galaxy from UKIDSS DR11 catalogue with reliable
photometry
false = otherwise
Note (2): IRAC magnitudes described in Dudzeviciute et al. (in preparation)
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Global Notes:
Note (G1): The ALMA ID comprises a 4-digit number giving the source identifier
from the parent S2CLS survey and a final digit which identifies the
individual galaxies detected with ALMA in each S2CLS source with
ascending numbers for descending flux
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 18-Nov-2022