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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, CB, Nakajima, R, Verdoes Kleijn, G, Amon, A, Choi, A, Covone, G, de Jong, JTA, Dvornik, A, Fenech Conti, I, Grado, A , Harnois-Déraps, J, Herbonnet, R, Hoekstra, H, Köhlinger, F, McFarland, J, Mead, A, Merten, J, Napolitano, N, Peacock, JA, Radovich, M, Schneider, P, Simon, P, Valentijn, EA, van den Busch, JL, van Uitert, E and Van Waerbeke, L (2016) KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing. Monthly Notices of the Royal Astronomical Society, 465 (2). pp. 1454-1498. ISSN 0035-8711

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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 Λ cold dark matter (ΛCDM) cosmology with a prior on H0 that encompasses the most recent direct measurements, we find 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 2.3σ 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.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords: 0201 Astronomical and Space Sciences
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: Oxford University Press (OUP)
Date Deposited: 23 Jul 2020 11:58
Last Modified: 23 Jul 2020 12:00
DOI or Identification number: 10.1093/mnras/stw2805
URI: http://researchonline.ljmu.ac.uk/id/eprint/13357

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