Hildebrandt, H;
Viola, M;
Heymans, C;
Joudaki, S;
Kuijken, K;
Blake, C;
Erben, T;
... Van Waerbeke, L; + view all
(2017)
KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing.
Monthly Notices of the Royal Astronomical Society
, 465
(2)
pp. 1454-1498.
10.1093/mnras/stw2805.
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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 ΛCDM cosmology with a prior on H0 that encompasses the most recent direct measurements, we find S8≡σ8Ωm/0.3−−−−−−√=0.745±0.039 S8≡σ8Ωm/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 2.3-σ 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.
| Type: | Article |
|---|---|
| Title: | KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stw2805 |
| Publisher version: | http://doi.org/10.1093/mnras/stw2805 |
| Language: | English |
| Additional information: | © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Hildebrandt, H; Viola, M; Heymans, C; Joudaki, S; Kuijken, K; Blake, C; Erben, T; (2017) KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing. Monthly Notices of the Royal Astronomical Society is available online at: http://doi.org/10.1093/mnras/stw2805 |
| Keywords: | Cosmology: observations, gravitational lensing: weak, galaxies: photometry, surveys |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1540190 |
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