J/MNRAS/469/492 JCMT/SCUBA2 objects in COSMOS and UDS fields (Michalowski+ 2017)
The SCUBA-2 Cosmology Legacy Survey:
the nature of bright submm galaxies from 2 deg2 of 850-µm imaging.
Michalowski M.J., Dunlop J.S., Koprowski M.P., Cirasuolo M., Geach J.E.,
Bowler R.A.A., Mortlock A., Caputi K.I., Aretxaga I., Arumugam V.,
Chen C.-C., Mclure R.J., Birkinshaw M., Bourne N., Farrah D., Ibar E.,
van der Werf P., Zemcov M.
<Mon. Not. R. Astron. Soc., 469, 492-515 (2017)>
=2017MNRAS.469..492M 2017MNRAS.469..492M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Redshifts ; Millimetric/submm sources ;
Radio sources ; Optical
Keywords: dust, extinction - galaxies: evolution - galaxies: high-redshift -
galaxies: star formation - galaxies: stellar content -
submillimetre: galaxies
Abstract:
We present physical properties [redshifts (z), star-formation rates
(SFRs) and stellar masses (M*)] of bright (S850≥4mJy) submm
galaxies in the ~=2deg2 COSMOS and UDS fields selected with
SCUBA-2/JCMT. We complete the galaxy identification process for all
(~=2000) S/N≥3.5 850-µm sources, but focus our scientific analysis
on a high-quality subsample of 651 S/N≥4 sources with complete
multiwavelength coverage including 1.1-mm imaging. We check the
reliability of our identifications, and the robustness of the SCUBA-2
fluxes by revisiting the recent ALMA follow-up of 29 sources in our
sample. Considering >4mJy ALMA sources, our identification method has
a completeness of ~=86 per cent with a reliability of ~=92 per cent,
and only ~=15-20 per cent of sources are significantly affected by
multiplicity (when a secondary component contributes >1/3 of the
primary source flux). The impact of source blending on the 850-µm
source counts as determined with SCUBA-2 is modest; scaling the
single-dish fluxes by ~=0.9 reproduces the ALMA source counts. For our
final SCUBA-2 sample, we find median z=2.40+0.10-0.04,
SFR=287±6M☉/yr and log(M*/M{sun)=11.12±0.02 (the latter
for 349/651 sources with optical identifications). These properties
clearly locate bright submm galaxies on the high-mass end of the 'main
sequence' of star-forming galaxies out to z~= 6, suggesting that major
mergers are not a dominant driver of the high-redshift submm-selected
population. Their number densities are also consistent with the
evolving galaxy stellar mass function. Hence, the submm galaxy
population is as expected, albeit reproducing the evolution of the
main sequence of star-forming galaxies remains a challenge for
theoretical models/simulations.
Description:
We have conducted an analysis of nearly 2000 submm sources detected in
the ∼2 deg2 850-um imaging of the COSMOS and UDS fields obtained
with SCUBA-2 on the JCMT as part of the SCUBA-2 Cosmology Legacy
Survey. This unique data set represents the largest homogeneous sample
of 850-um-selected sources assembled to date, and we have exploited
this sample, along with the rich multiwavelength supporting data in
these fields to shed new light on the physical properties and
cosmological evolution of bright (S850≥4mJy) submm-selected
galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cosmos.dat 802 826 JCMT/SCUBA2 objects in the COSMOS field
(tables A1, A3, A5, A7)
COSMOS_mr.fits 2880 234 Fits version of cosmos.dat
uds.dat 802 1247 JCMT/SCUBA2 objects in the UDS field
(tables A2, A4, A6, A8)
UDS_mr.fits 2880 349 Fits version of uds.dat
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Byte-by-byte Description of file: cosmos.dat uds.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right ascension of a SCUBA-2 source (J2000)
11- 21 F11.7 deg DEdeg Declination of a SCUBA-2 source (J2000)
23- 26 I4 --- Num850 Running number of a SCUBA-2 source
28- 32 F5.2 mJy F850 Flux density of a SCUBA-2 source
34- 37 F4.2 mJy e_F850 Error on F850
39- 47 F9.5 deg RAIDdeg ?=-99 Right ascension of an ID (J2000)
49- 59 F11.7 deg DEIDdeg ?=-99 Declination of an ID (J2000)
61- 69 F9.5 deg RA14deg ?=-99 Right ascension of a radio ID (J2000)
71- 81 F11.7 deg DE14deg ?=-99 Declination of an ID (J2000)
83- 87 I5 uJy F14 ?=-99 Radio flux density at 14GHz
89- 92 I4 uJy e_F14 ?=-99 Error on F14
94- 99 F6.2 arcsec Sep850-14 ?=-99 Distance of a radio ID from
the 850um position
101-108 F8.4 --- P14 ?=-99 Probability of a chance association
110-118 F9.5 deg RA8deg ?=-99 Right ascension of a 8.0um ID (J2000)
120-130 F11.7 deg DE8deg ?=-99 Declination of a 8.0um ID (J2000)
132-138 F7.2 uJy F8 ?=-99 8.0 um flux density
140-145 F6.2 uJy e_F8 ?=-99 Error on F8
147-152 F6.2 arcsec Sep850-8 ?=-99 Distance of an 8.0 um ID from
the 850um position
154-161 F8.4 --- P8 ?=-99 Probability of a chance association
163-171 F9.5 deg RA24deg ?=-99 Right ascension of a 24 um ID (J2000)
173-183 F11.7 deg DE24deg ?=-99 Declination of a 24 um ID (J2000)
185-189 I5 uJy F24 ? 24 um flux density
191-193 I3 uJy e_F24 ?=-99 Error on F24
195-200 F6.2 arcsec Sep850-24 ?=-99 Distance of a 24 um ID from
the 850um position
202-209 F8.4 --- P24 ?=-99 Probability of a chance association
211-216 F6.2 Jy F100 ?=-99 100 um flux density
218-223 F6.2 Jy e_F100 ?=-99 Error on F100
225-230 F6.2 Jy F160 ?=-99 160 um flux density
232-237 F6.2 Jy e_F160 ?=-99 Error on F160
239-242 F4.2 Jy F250 250 um flux density
244-247 F4.2 Jy e_F250 Error on F250
249-252 F4.2 Jy F350 350 um flux density
254-257 F4.2 Jy e_F350 Error on F350
259-262 F4.2 Jy F500 500 um flux density
264-267 F4.2 Jy e_F500 Error on F500
269-276 F8.4 --- Pbest The best (radio, 24 or 8.0) probability of
chance alignment
278-283 F6.2 Jy F11 ?=-99 1.1 mm flux density
285-290 F6.2 Jy e_F11 ?=-99 Error on F11
292-300 F9.5 deg RAAzdeg ?=-99 Right ascension of an AzTEC 1.1 mm
source (J2000)
302-312 F11.7 deg DEAzdeg ?=-99 Declination of an AzTEC 1.1 mm
source (J2000)
314-319 F6.2 arcsec Sep850-Az ?=-99 distance of an AzTEC source from
the 850um position
321 I1 --- useID [1/5] Use ID code (1)
323-326 F4.2 --- zLWlow long-wavelength redshift
(based on 100 um - 1.1mm)
328-331 F4.2 --- e_zLWlow Minus error on zLWlow
333-336 F4.2 --- E_zLWlow Plus error on zLWlow
338-346 F9.4 deg RAOdeg ?=-99 Right ascension of an optical
counterpart (J2000)
348-357 F10.6 deg DEOdeg ?=-99 Declination of an optical
counterpart (J2000)
359-367 E9.3 Jy F0.374 ?=-99 0.374 um flux density
369-377 E9.3 Jy e_F0.374 ?=-99 Error on F0.374
379-387 E9.3 Jy F0.487 ?=-99 0.487 um flux density
389-397 E9.3 Jy e_F0.487 ?=-99 Error on F0.487
399-407 E9.3 Jy F0.625 ?=-99 0.625 um flux density
409-417 E9.3 Jy e_F0.625 ?=-99 Error on F0.625
419-427 E9.3 Jy F0.77 ?=-99 0.77 um flux density
429-437 E9.3 Jy e_F0.77 ?=-99 Error on F0.77
439-447 E9.3 Jy F0.9 ?=-99 0.9 um flux density
449-457 E9.3 Jy e_F0.9 ?=-99 Error on F0.9
459-467 E9.3 Jy F1.0 ?=-99 1.0 um flux density
469-477 E9.3 Jy e_F1.0 ?=-99 Error on F1.0
479-487 E9.3 Jy F1.25 ?=-99 1.25 um flux density
489-497 E9.3 Jy e_F1.25 ?=-99 Error on F1.25
499-507 E9.3 Jy F1.65 ?=-99 1.65 um flux density
509-517 E9.3 Jy e_F1.65 ?=-99 Error on F1.65
519-527 E9.3 Jy F2.15 ?=-99 2.15 um flux density
529-537 E9.3 Jy e_F2.15 ?=-99 Error on F2.15
539-547 E9.3 Jy F3.6 ?=-99 3.6 um flux density
549-557 E9.3 Jy e_F3.6 ?=-99 Error on F3.6
559-567 E9.3 Jy F4.5 ?=-99 4.5 um flux density
569-577 E9.3 Jy e_F4.5 ?=-99 Error on F4.5
579-584 F6.2 arcsec SepID-O ?=-99 Distance of an optical source
from the ID position
586-591 F6.2 --- zopt ?=-99 Photometric optical redshift
593-598 F6.2 --- e_zopt ?=-99 Minus error on zopt
600-605 F6.2 --- E_zopt ?=-99 Plus error on zopt
607-612 F6.2 [Msun] logMass ?=-99 log10(stellar mass)
614-619 F6.2 --- fmassold ?=-99 Fraction of stellar mass in
the old component
621-626 F6.2 --- AV-young ?=-99 Extinction of the young component
628-633 F6.2 Gyr Age-young ?=-99 Age of the young component
635-640 F6.2 --- AV-old Extinction of the old component
642-647 F6.2 Gyr Age-old Age of the old component
649-652 F4.2 --- zuse Adopted redshift
654-658 F5.2 --- E_zuse Plus error on zuse
660-663 F4.2 --- e_zuse Minus error on zuse
665 I1 --- ztype [1/3] z type (2)
667-677 E11.6 Lsun LIR 8-1000 um luminosity using the submm
galaxy template
679-689 E11.6 Lsun e_LIR Error on LIR
691-697 F7.2 Msun/yr SFR Star formation rate using the submm
galaxy template
699-705 F7.2 Msun/yr e_SFR Error on SFR
707-714 F8.2 Gyr-1 sSFR ?=-99 Specific SFR using the submm
galaxy template
716-722 F7.2 Gyr-1 e_sSFR ?=-99 error on sSFR
724-734 E11.6 Lsun LIRArp 8-1000 um luminosity using the Arp220
template
736-746 E11.6 Lsun e_LIRArp Error on LIRArp
748-754 F7.2 Msun/yr SFRArp Star formation rate using the Arp220
template
756-762 F7.2 Msun/yr e_SFRArp Error on SFRArp
764-771 F8.2 Gyr-1 sSFRArp ?=-99 Specific SFR using the Arp220 template
773-780 F8.2 Gyr-1 e_sSFRArp ?=-99 Error on sSFRArp
782-788 F7.2 Msun/yr SFR850 Star formation rate using only
the 850um datapoint
790-796 F7.2 Msun/yr e_SFR850 Error on SFR850
798-802 F5.2 --- SN850 Signal-to-noise ratio of
the SCUBA-2 detection
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Note (1): Use ID code as follows:
1 = primaryID
2 = secondaryID
3 = tetriaryID, etc
Note (2): ztype as follows:
1 = optical
2 = long-wavelength
3 = long-wavelength after rejection of the optical
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Mar-2020