II/384 KiDS-450: Weak lensing shear measurements (Hildebrandt+, 2017)
KiDS-450: cosmological parameter constraints from tomographic weak gravitational
lensing.
Hildebrandt H., Viola M., Heymans C., Joudaki S., Kuijken K., Blake C.,
Erben T., Joachimi B., Klaes D., Miller L., Morrison C.B., Nakajima R.,
Verdoes Kleijn G., Amon A., Choi A., Covone G., de Jong J.T.A., Dvornik A.,
Fenech Conti I., Grado A., Harnois-Deraps J., Herbonnet R., Hoekstra H.,
Kohlinger F., McFarland J., Mead A., Merten J., Napolitano N., Peacock J.A.,
Radovich M., Schneider P., Simon P., Valentijn E.A., van den Busch J.L.,
van Uitert E., van Waerbeke L.
<Mon. Not. R. Astron. Soc., 465, 1454-1498 (2017)>
=2017MNRAS.465.1454H 2017MNRAS.465.1454H
ADC_Keywords: Photometry, ugriz ; Galaxy catalogs; Redshifts;
Gravitational lensing
Mission_Name: ESO
Keywords: gravitational lensing: weak - surveys - galaxies: photometry -
cosmology: observations - cosmology: observations
Abstract:
We present cosmological parameter constraints from a tomographic weak
gravitational lensing analysis of ∼450deg2 of imaging data from the
Kilo Degree Survey (KiDS). For a flat Λ cold dark matter
(ΛCDM) cosmology with a prior on H0 that encompasses the most
recent direct measurements, we find
S8=σ8(Ωm/0.3)0.5=0.745±0.039. This result is
in good agreement with other low-redshift probes of large-scale
structure, including recent cosmic shear results, along with
pre-Planck cosmic microwave background constraints. A 2.3σ
tension in S8 and "substantial discordance" in the full parameter
space is found with respect to the Planck 2015 results. We use shear
measurements for nearly 15 million galaxies, determined with a new
improved "self-calibrating" version of lensfit validated using an
extensive suite of image simulations. Four-band ugri photometric
redshifts are calibrated directly with deep spectroscopic surveys. The
redshift calibration is confirmed using two independent techniques
based on angular cross-correlations and the properties of the
photometric redshift probability distributions. Our covariance matrix
is determined using an analytical approach, verified numerically with
large mock galaxy catalogues. We account for uncertainties in the
modelling of intrinsic galaxy alignments and the impact of baryon
feedback on the shape of the non-linear matter power spectrum, in
addition to the small residual uncertainties in the shear and redshift
calibration. The cosmology analysis was performed blind. Our
high-level data products, including shear correlation functions,
covariance matrices, redshift distributions, and Monte Carlo Markov
chains are available at http://kids.strw.leidenuniv.nl/
Description:
This catalogue data release contains the weak lensing shear
measurements from the KiDS-450 data set, which corresponds to the
survey area of the third public release of the Kilo-Degree Survey
(KiDS). KiDS is an ESO public survey carried out with the VLT Survey
Telescope (VST) and OmegaCAM camera, that will image 1500 square
degrees in four filters (u, g, r, i), in single epochs per filter.
KiDS is designed to be a weak lensing shear tomography survey, and has
as its core science drivers mapping of the large-scale matter
distribution in the universe and constraining the equation-of-state of
Dark Energy.
Observations are carried out in the SDSS-like u, g, r, and i bands
with total exposure times of 17, 15, 30, and 20 min, respectively.
This yields limiting magnitudes of 24.3, 25.1, 24.9, 23.8 (5σ in
a 2-arcsec aperture) in ugri, respectively. The observations are
queue-scheduled such that the best-seeing dark time is reserved for
the r-band images, which are used to measure the shapes of galaxies
(see Section 2.5). KiDS targets two ∼10x75deg2 strips, one on the
celestial equator (KiDS-N) and the other around the South Galactic
Pole (KiDS-S).
This catalogue release constitutes the first official release of weak
lensing shear data by KiDS and corresponds almost exactly with the
area for which other data products were released in the pre- ceding
general KiDS data releases (DR1, DR2 and DR3).
Only galaxies with reliable shape measurements are included in this
catalogue.
The data were taken under ESO programme IDs: 177.A-3016(A),
177.A-3016(B), 177.A-3016(C), 177.A-3016(D), 177.A-3016(E),
177.A-3016(G), 177.A-3016(J), 177.A-3016(K), 177.A-3017(A), and
177.A-3018(A).
Acknowledging KiDS in publications:
Please include the following acknowledgment in any published material
that makes use of this data product:
Based on data obtained from the ESO Science Archive Facility with DOI:
https://doi.org/10.18727/archive/37
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
kids_shear.sam 425 1000 *The Kilo-Degree Survey (KiDS) ESO weak lensing
shear measurements catalog (DR3.1)
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Note on kids_shear.sam: This is a sample of the complete catalog
containing 14,650,348 sources.
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Description of file:
release-description-KiDS-450.pdf is the ESO Phase 3 Data Release
Description for this catalog downloaded at:
http://www.eso.org/rm/api/v1/public/releaseDescriptions/99
See also:
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
II/329 : VIKING catalogue data release 1 (Edge+, 2013)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
II/350 : VLT Survey Telescope ATLAS (Shanks+, 2015)
II/344 : KiDS-ESO-DR2 multi-band source catalog (de Jong+, 2015)
II/343 : VIKING catalogue data release 2 (Edge+, 2016)
II/347 : KiDS-ESO-DR3 multi-band source catalog (de Jong+, 2017)
J/ApJS/184/218 : The zCOSMOS 10k-bright spectroscopic sample (Lilly+, 2009)
J/MNRAS/413/971 : Galaxy And Mass Assembly (GAMA) DR1 (Driver+, 2011)
J/A+A/568/A22 : Joint analysis of the SDSS-II & SNLS SNe Ia (Betoule+, 2014)
J/ApJS/216/27 : Galaxy clusters in the SPT-SZ survey (Bleem+, 2015)
J/MNRAS/449/835 : Clustering of SDSS DR7 main galaxy sample. I. (Ross+, 2015)
J/AJ/150/31 : Phot. and redshifts of galaxies in the UDF (Rafelski+, 2015)
J/ApJS/224/24 : The COSMOS2015 catalog (Laigle+, 2016)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/A+A/594/A27 : Planck Sunyaev-Zeldovich sources (PSZ2) (Planck+, 2016)
J/A+A/632/A34 : KiDS+VIKING-450 opt+NIR dataset (Wright+, 2019)
J/A+A/633/A69 : KiDS-VIKING-450 cosmic shear (Hildebrandt+, 2020)
J/ApJ/893/4 : KiDS ultracompact massive gal. sp. obs. (Scognamiglio+, 2020)
Byte-by-byte Description of file: kids_shear.sam
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Bytes Format Units Label Explanations
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1- 25 A25 --- ID Source identifier
(KIDS JHHMMSS.ss+DDMMSS.ss) (1)
27- 42 F16.12 deg RAdeg Right ascension of barycenter (J2000)
(RAJ2000)
44- 59 F16.12 deg DEdeg Declination of barycenter (J2000)
(DECJ2000)
61- 63 A3 --- Patch Patch (G9, G12, G15, G23 or GS);
see Section 2.1
65- 71 I7 --- Seq Running object number within the patch
(SeqNr)
73- 88 A16 --- Tile Name of the KiDS survey tile (KIDS_TILE)
90- 105 A16 --- TileTHELI THELI name for the tile (THELI_NAME)
107- 109 I3 --- Mask [0/962] Bit mask indicating sources
affected by different types of defects (2)
111- 113 F3.1 --- FlS/G [0/1] Star-galaxy separator
(0=star, 1=galaxy) (SG_FLAG)
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115- 121 F7.4 pix Rad [3.5/10.6] Scaling radius of the ellipse
for magnitude measurements (KRON_RADIUS)
123- 132 F10.4 pix Xpos Object position along x in the r-band
THELI stack (non unique)
134- 143 F10.4 pix Ypos Object position along y in the r-band
THELI stack (non unique)
145- 152 F8.4 pix rFWHMimg [0/154]? r-band FWHM assuming a Gaussian
core (FWHM_IMAGE)
154- 159 F6.4 deg rFWHM [0/0.01]? r-band FWHM assuming a Gaussian
core (FWHM_WORLD)
161- 162 I2 --- Flag [0/18] r-band SExtractor extraction flags
164- 170 F7.4 pix rrhalf [0.7/92]? r-band half-light radius
(FLUX_RADIUS)
172- 177 F6.4 --- S/G [0/1] r-band SExtractor S/G classifier
output (CLASS_STAR)
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179- 186 F8.5 mag umag0GAAP [16/26.1]? Magnitude in the u-band
(GAaP, dereddened) (MAG_u) (3)
188- 194 F7.5 mag e_umag0GAAP [1.8e-4/1.1]? Magnitude error in the
u-band (MAGERR_u)
196- 203 F8.5 mag gmag0GAAP [16.9/26.8]? Magnitude in the g-band
(GAaP, dereddened) (MAG_g) (3)
205- 211 F7.5 mag e_gmag0GAAP [2.9e-4/1.1]? Magnitude error in the
g-band (MAGERR_g)
213- 220 F8.5 mag rmag0GAAP [19/26.5]? Magnitude in the r-band
(GAaP, dereddened) (MAG_r) (3)
222- 228 F7.5 mag e_rmag0GAAP [0.001/1.1]? Magnitude error in the r-band
(MAGERR_r)
230- 237 F8.5 mag imag0GAAP [17.7/26]? Magnitude in the i-band
(GAaP, dereddened) (MAG_i) (3)
239- 245 F7.5 mag e_imag0GAAP [0.001/1.1]? Magnitude error in the i-band
(MAGERR_i)
247- 254 F8.5 mag umagLim [23.2/26.3]? Limiting magnitude in the
u-band (MAGLIMu)
256- 263 F8.5 mag gmagLim [23.5/27]? Limiting magnitude in the
g-band (MAGLIMg)
265- 272 F8.5 mag rmagLim [24.7/26.8] Limiting magnitude in the
r-band (MAGLIMr)
274- 281 F8.5 mag imagLim [22.9/26.1]? Limiting magnitude in the
i-band (MAGLIMi)
283- 290 F8.5 mag ZPoff [-0.32/0.26] Zeropoint offset derived from
GAIA DR1 G photometry (ZPT_offset) (4)
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292- 295 F4.2 --- zbest [0/3.5] BPZ best redshift estimate (Z_B)
297- 301 F5.3 --- b_zbest [0/2.61] Lower bound of the 95% confidence
interval of zbest (ZBMIN)
303- 307 F5.3 --- B_zbest [0.1/4.1] Upper bound of the 95%
confidence interval of zbest (ZBMAX)
309- 313 F5.3 --- Tzbest [1/6] Spectral type corresponding to zbest
(T_B) (5)
315- 321 F7.5 --- Odds [0.02/1] Empirical ODDS of zbest (ODDS) (6)
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323- 324 I2 --- FitClass [-9/0]? Lensfit: fit class (fitclass) (7)
326- 332 F7.4 pix ScaleLength [-0.5/17.6] Lensfit: galaxy model
scalelength (biascorrectedscalelength)
334- 340 F7.5 --- B/T [0/1] Lensfit: galaxy model bulge-fraction
B/T (bulge_fraction)
342- 347 F6.1 ct Flux [0.5/1391] Lensfit: galaxy model flux
(model_flux)
349- 354 F6.1 --- SNR [1.2/1753] Lensfit: data S/N ratio
(pixel_SNratio)
356- 364 F9.4 --- SNR-model [1.9/1466] Lensfit: model S/N ratio
(model_SNratio)
366- 370 F5.2 pix Rcont [4.4/99] Lensfit: distance to nearest
contaminating isophote
(contamination_radius)
372- 377 F6.3 --- PSFe1 [-0.14/0.11] Lensfit: PSF model mean
ellipticity e1 (PSF_e1)
379- 384 F6.3 --- PSFe2 [-0.15/0.12] Lensfit: PSF model mean
ellipticity e2 (PSF_e2)
386- 391 F6.4 --- Strehl [0/0.17] Lensfit: PSF model mean
pseudo-Strehl ratio (PSFStrehlratio)
393- 399 F7.4 --- e1 [-0.98/0.99] Lensfit: galaxy e1
expectation value
401- 407 F7.4 --- e2 [-0.93/0.92] Lensfit: galaxy e2
expectation value
409- 415 F7.4 --- Weight [0.01/15.6] Lensfit: inverse variance
shear weight (weight)
417- 425 F9.6 --- MultCal [-0.91/0.3] Multiplicative shear
calibration (m) (8)
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Note (1): Please note that the source IDs in this catalogue may differ slightly
from the ones included in the KiDS DR3.0 release (see II/347).
Note (2): Automatic and manual masks produced during data processing flag areas
affected by bright stars (e.g. saturated pixels, reflection halos,
diffraction and readout spikes) and other severe image defects. In the
released catalogue the most strongly affected regions are already
removed, 3 leaving only sources with reliable measurements. As a
result, only the following bit mask values are present:
2 = Faint stellar reflection halo
64 = u-band AstroWISE manual mask
128 = g-band AstroWISE manual mask
256 = r-band AstroWISE manual mask
512 = i-band AstroWISE manual mask
Note (3): The magnitudes are based on Gaussian Aperture and Photometry (GAaP)
measurements and are dereddened and colour-calibrated using stellar
locus regression. Note: these aperture magnitudes are mainly intended
for colour measurements, since they only probe the central regions of
the source. They are not total magnitudes, except in the case of
unresolved or point sources.
Note (4): The magnitudes reported in this catalogue have been colour-calibrated,
but their absolute calibration has only been homogenized per survey
tile, not over the full area. Based on a comparison (see de Jong+ 2016,
in prep) of the r-band magnitudes with the GAIA DR1 (GAIA Col., 2016,
arXiv:1609.04172) we provide these additional photometric offsets that
can be used to homogenize the photometry over the whole catalogue. The
reported offsets are with respect to the GAIA photometry, but can be
used to calibrate the photometry to the SDSS photometric system as
follows:
magu/g/r/ihomogenized = mag_u/g/r/i - ZPT_offset + 0.049
Note: if used, these offsets must be applied to the magnitudes in all
filters!
Note (5): the best-fit spectral template for each source; these values
correspond to the following types, where fractional types can occur
because the templates are interpolated:
1 = CWW-Ell,
2 = CWW-Sbc,
3 = CWW-Scd,
4 = CWW-Im,
5 = KIN-SB3,
6 = KIN-SB2
(Capak, 2004, PhD. thesis, Univ. Hawai'i).
Note (6): A measure of the uni-modality of the redshift Probability
Distribution Function; a higher value indicates a higher reliability
of the best photo-z estimate.
Note (7): lensfit object class; the only classes included in the catalogue
are as follows:
0 = galaxy, no issues and
-9 = large galaxy, overfills 48 pixel postage stamp size.
The latter class is retained to avoid ellipticity selection bias in
the brightest galaxy sample.
Note (8): The multiplicative shear calibration correction which should be
applied in an ensemble average, rather than on a galaxy-by-galaxy
basis (see Fenech Conti+ 2016 arXiv:1606.05337). Averaged catalogued
ellipticities should be divided by 1+, where the ellipticities
should be weighted with the lensfit weight.
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History:
Downloaded from: http://www.eso.org/qi/catalog/show/138
License: CC BY 4.0
(End) F.-X. Pineau, K. Voggel, E. Perret [CDS] 27-Mar-2025