J/ApJS/240/5 SHELA. II. DECam and IRAC multiwavelength catalog (Wold+, 2019)
The Spitzer-HETDEX Exploratory Large Area survey.
II. The Dark Energy Camera and Spitzer/IRAC multiwavelength catalog.
Wold I.G.B., Kawinwanichakij L., Stevans M.L., Finkelstein S.L.,
Papovich C., Devarakonda Y., Ciardullo R., Feldmeier J., Florez J.,
Gawiser E., Gronwall C., Jogee S., Marshall J.L., Sherman S., Shipley H.V.,
Somerville R.S., Valdes F., Zeimann G.R.
<Astrophys. J. Suppl. Ser., 240, 5-5 (2019)>
=2019ApJS..240....5W 2019ApJS..240....5W (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry; Photometry, ugriz; Photometry, infrared ;
Redshifts; Surveys
Keywords: catalogs; cosmology: observations; galaxies: photometry; surveys
Abstract:
We present the ugriz-band Dark Energy Camera (DECam) plus 3.6 and
4.5µm IRAC catalogs for the Spitzer/HETDEX Exploratory Large-Area
(SHELA) survey. SHELA covers ∼24deg2 of the Sloan Digital Sky Survey
(SDSS) "Stripe 82" region, with seven bandpasses spanning a wavelength
range of 0.35 to 4.5µm. SHELA falls within the footprint of the
Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), which will
provide spectroscopic redshifts for ∼200000 Lyα emitters at
1.9<z<3.5 and also for ∼200000 [OII] emitters at z<0.5. SHELA's deep,
wide-area multiwavelength images, combined with HETDEX's spectroscopic
information, will facilitate many extragalactic studies, including
measuring the evolution of galaxy stellar mass, halo mass, and
environment from 1.5<z<3.5. Here we present riz-band-selected
ugriz-band DECam catalogs that reach a 5σ depth of ∼24.5 AB mag
(for point sources with an aperture that encloses 70% of the total
flux) and cover 17.5deg2 of the overall SHELA field. We validate our
DECam catalog by comparison to the DECam Legacy Survey (DECaLS) DR5
and the Dark Energy Survey (DES) DR1. We perform IRAC forced
photometry with The Tractor image modeling code to measure 3.6 and
4.5µm fluxes for all objects within our DECam catalog. We
demonstrate the utility of our catalog by computing galaxy number
counts and estimating photometric redshifts. Our photometric redshifts
recover the available =0.33 SDSS spectroscopic redshifts with a
1σ scatter in Δz/(1+z) of 0.04.
Description:
We observed with the Blanco 4m telescope at CTIO using the 3deg2
DECam imager and the u-, g-, r-, i-, and z-band filters. Data were
obtained over 5 nights in the 2013B semester (PI: Papovich;
NOAO PID: 2013B-0438). As shown in Figure 1, we observed six slightly
overlapping pointings covering a total area of 17.5deg2.
We supplement our data with overlapping DES DR1 data.
To construct a mixed-resolution multiband catalog of DECam ugriz +
Spitzer/IRAC 3.6 and 4.5um bands, we supply The Tractor modeling code
with the input image of Spitzer/HETDEX Exploratory Large-Area (SHELA)
IRAC 3.6 and 4.5um images (Papovich+ 2016ApJS..224...28P 2016ApJS..224...28P).
See Section 4.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 479 2193428 Spitzer/HETDEX Exploratory Large-Area (SHELA)
Dark Energy Camera (DECam) catalog
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See also:
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)
J/ApJS/162/1 : MUSYC: optical source catalog (Gawiser+, 2006)
J/ApJS/206/8 : COSMOS/UltraVISTA Ks-selected catalogs v4.1 (Muzzin+, 2013)
J/ApJS/231/7 : The VISTA-CFHT Stripe 82 NIR survey (VICS82) (Geach+, 2017)
http://irsa.ipac.caltech.edu/data/SPITZER/SHELA/ : SHELA data access on IRSA
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Unique object ID number (B3_ to B6_ tiles plus
000001 to 684409 numbers)
11- 19 F9.6 deg RAdeg [14/24.6] Right Ascension (J2000)
21- 29 F9.6 deg DEdeg [-1.4/1.4] Declination (J2000)
31- 36 F6.1 arcsec amaj [0.1/3048] Semimajor axis (1)
38- 41 F4.2 --- ell [0/1] Ellipticity (1)
43- 47 F5.1 deg PA [-90/90] Postion angle (1)
49- 53 F5.1 --- rKron [0/877] Sextractor Kron radius, AUTO
photometry (1)
55- 61 F7.1 arcsec r0.5 [0/15905] PSF half-light radius (1)
63- 69 F7.3 uJy FuPSF [-4/993] DECam u-band PSF fitting flux (2)
71- 76 F6.3 uJy e_FuPSF [0.001/46] Uncertainty in FuPSF (5)
78- 86 F9.3 uJy Fu [-132/46824] CTIO/DECam u-band AUTO aperture
flux (3)
88- 95 F8.3 uJy e_Fu [0.001/2942] Uncertainty in Fu (5)
97- 99 I3 --- uflI [0/153] DECam u-band Sextractor internal
flag (4)
101 I1 --- uflE [0/1] DECam u-band Sextractor external flag (4)
103- 111 F9.3 uJy FgPSF [-4/34050] DECam g-band PSF fitting flux (2)
113- 120 F8.3 uJy e_FgPSF [0.001/1570] Uncertainty in FgPSF (5)
122- 131 F10.3 uJy Fg [-21/521598] CTIO/DECam g-band AUTO aperture
flux (3)
133- 141 F9.3 uJy e_Fg [0.001/24346] Uncertainty in Fg (5)
143- 145 I3 --- gflI [0/153] DECam g-band Sextractor internal
flag (4)
147 I1 --- gflE [0/1] DECam Sextractor g-band external flag (4)
149- 157 F9.3 uJy FrPSF [-6/19361] DECam r-band PSF fitting flux (2)
159- 165 F7.3 uJy e_FrPSF [0.001/892] Uncertainty in FrPSF (5)
167- 176 F10.3 uJy Fr [-54/366386] CTIO/DECam r-band AUTO aperture
flux (3)
178- 186 F9.3 uJy e_Fr [0.001/29114] Uncertainty in Fr (5)
188- 190 I3 --- rflI [0/157] DECam r-band Sextractor internal
flag (4)
192 I1 --- rflE [0/1] DECam r-band Sextractor external flag (4)
194- 202 F9.3 uJy FiPSF [-7/16418] DECam i-band PSF fitting flux (2)
204- 210 F7.3 uJy e_FiPSF [0.001/758] Uncertainty in FiPSF (5)
212- 221 F10.3 uJy Fi [-1135/743848] CTIO/DECam i-band AUTO
aperture flux (3)
223- 232 F10.3 uJy e_Fi [0.001/220928] Uncertainty in Fi (5)
234- 236 I3 --- iflI [0/157] DECam i-band Sextractor internal
flag (4)
238 I1 --- iflE [0/1] DECam i-band Sextractor external flag (4)
240- 248 F9.3 uJy FzPSF [-5/47832] DECam z-band PSF fitting flux (2)
250- 257 F8.3 uJy e_FzPSF [0.001/2216] Uncertainty in FzPSF (5)
259- 268 F10.3 uJy Fz [-322/568888] CTIO/DECam z-band AUTO aperture
flux (3)
270- 279 F10.3 uJy e_Fz [0.001/161580] Uncertainty in Fz (5)
281- 283 I3 --- zflI [0/157] DECam z-band Sextractor internal
flag (4)
285 I1 --- zflE [0/1] DECam z-band Sextractor external flag (4)
287- 292 A6 --- --- [VICS82]
293- 311 A19 --- VICS82 JK object ID number (JHHMMSS.ss+DDMMSS.s),
Geach+ (2017, J/ApJS/231/7)
313- 321 F9.2 uJy FJ [0.01/948492]?=-99 J band AUTO aperture flux
(6)
323- 329 F7.2 uJy e_FJ [0/4153]?=-99 Uncertainty in FJ (6)
331- 339 F9.2 uJy FK [0/921168]?=-99 K band AUTO aperture flux (6)
341- 348 F8.2 uJy e_FK [0/37964]?=-99 Uncertainty in FK (6)
350- 360 F11.2 uJy F3.6um [-5e+6/2.1e+6]?=-99 Spitzer/IRAC 3.6um
Tractor total flux
362- 377 F16.2 uJy e_F3.6um [0.01/5e+12]?=-99 Uncertainty in F3.6um
379 I1 --- Mod3.6 [0/4]? IRAC Tractor model profile, 3.6um (7)
381- 395 F15.2 --- logP3.6 [-7e+10/0] IRAC Tractor log-probability,
3.6um
397 I1 --- Tfl3.6 [0/2] Tractor flag, 3.6um observation (8)
399- 409 F11.2 uJy F4.5um [-1e+6/1.3e+6]?=-99 Spitzer/IRAC 4.5um
Tractor total flux
411- 426 F16.2 uJy e_F4.5um [0.01/3e+12]?=-99 Uncertainty in F4.5um
428 I1 --- Mod4.5 [0/4]? IRAC Tractor model profile, 4.5um (7)
430- 444 F15.2 --- logP4.5 [-3e+10/0] IRAC Tractor log-probability, 4.5um
446 I1 --- Tfl4.5 [0/2] Tractor flag, 4.5um observation (8)
448- 453 F6.2 --- zspec [0/1.7]?=-99 SDSS spectroscopic redshift
455- 460 F6.2 --- zpeak [0.01/10.5]?=-99 EAZY peak photometric
redshift
462- 467 F6.2 --- za [0.01/11]?=-99 EAZY χ2 minimum
photometric redshift
469- 475 F7.2 --- chi2a [0/2664]?=-99 EAZY χ2 minimum value
477- 479 I3 --- Nfilt [5/9]?=-99 EAZY number of filters
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Note (1): PSF shape parameters in the detection image include:
amaj = semimajor axis in the detection image, arcsec;
ell = ellipticity measured in the detection image, defined as e=1-b/a,
where b and a are the semiminor and semimajor axes, respectively;
PA = position angle measured in the detection image (degrees E from N);
rKron = Sextractor Kron radius used in AUTO photometry;
r0.5 = Sextractor half-light radius, FLUX RADIUS.
Note (2): DECam ugriz PSF fluxes appropriate for unresolved sources;
Note (3): DECam ugriz total (Kron) fluxes appropriate for resolved sources;
Note (4): Internal and external (DGM based) flags; see Sextractor Users Manual.
Internal SExtractor flags >3 denote saturated, truncated, or corrupted
pixels.
Note (5): Given the catalog's convention of rounding to the nearest
thousandth decimal place for DECam fluxes, there are rare cases where
the rounded DECam flux error equals "0.000". All "0.000" flux error
sources have non-zero flags indicating extraction problems and should be
utilized with caution. To avoid null values, we adopt a minimum flux
error of "0.001" for these sources.
Note (6): JK total (Kron) fluxes and errors from Geach+ (2017, J/ApJS/231/7).
Note (7): Tractor model profiles as follows:
0 = point source;
1 = exponential
4 = de Vaucouleurs profile
See Section 4.2.
Note (8): Tractor flags as follows:
0 = no flag;
1 = 5σ outliers from the existing SHELA IRAC SExtractor catalog
2 = nonoptimized Tractor extraction
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History:
From electronic version of the journal
References:
Papovich et al. Paper I. 2016ApJS..224...28P 2016ApJS..224...28P
Wold et al. Paper II. 2019ApJS..240....5W 2019ApJS..240....5W This catalog
Leung et al. Paper IV. 2023ApJS..269...46L 2023ApJS..269...46L Cat. J/ApJS/269/46
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-May-2019