KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing
Date Issued
2017
Author(s)
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.
•
•
Harnois-Déraps, J.
•
Herbonnet, R.
•
Hoekstra, H.
•
Köhlinger, F.
•
McFarland, J.
•
Mead, A.
•
•
•
Peacock, J. A.
•
•
Schneider, P.
•
Simon, P.
•
Valentijn, E. A.
•
van den Busch, J. L.
•
van Uitert, E.
•
Van Waerbeke, L.
Abstract
We present cosmological parameter constraints from a tomographic weak gravitational lensing analysis of ∼450 deg2 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 S_8≡ σ _8√{Ω _m/0.3}=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.
Volume
465
Issue
2
Start page
1454
Issn Identifier
0035-8711
Ads BibCode
2017MNRAS.465.1454H
Rights
open.access
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