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KiDS+GAMA: cosmology constraints from a joint analysis of cosmic shear, galaxy–galaxy lensing, and angular clustering

van Uitert, E, Joachimi, B, Joudaki, S, Amon, A, Heymans, C, Köhlinger, F, Asgari, M, Blake, C, Choi, A, Erben, T, Farrow, DJ, Harnois-Déraps, J, Hildebrandt, H, Hoekstra, H, Kitching, TD, Klaes, D, Kuijken, K, Merten, J, Miller, L, Nakajima, R , Schneider, P, Valentijn, E and Viola, M (2018) KiDS+GAMA: cosmology constraints from a joint analysis of cosmic shear, galaxy–galaxy lensing, and angular clustering. Monthly Notices of the Royal Astronomical Society, 476 (4). pp. 4662-4689. ISSN 0035-8711

KiDS+GAMA cosmology constraints from a joint analysis of cosmic shear, galaxy–galaxy lensing, and angular clustering.pdf - Published Version

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We present cosmological parameter constraints from a joint analysis of three cosmological probes: the tomographic cosmic shear signal in ∼450 deg2 of data from the Kilo Degree Survey (KiDS), the galaxy-matter cross-correlation signal of galaxies from the Galaxies And Mass Assembly (GAMA) survey determined with KiDS weak lensing, and the angular correlation function of the same GAMA galaxies. We use fast power spectrum estimators that are based on simple integrals over the real-space correlation functions, and show that they are practically unbiased over relevant angular frequency ranges. We test our full pipeline on numerical simulations that are tailored to KiDS and retrieve the input cosmology. By fitting different combinations of power spectra, we demonstrate that the three probes are internally consistent. For all probes combined, we obtain S8≡σ8Ωm/0.3−−−−−−√=0.800+0.029−0.027⁠, consistent with Planck and the fiducial KiDS-450 cosmic shear correlation function results. Marginalizing over wide priors on the mean of the tomographic redshift distributions yields consistent results for S8 with an increase of 28percent in the error. The combination of probes results in a 26 per cent reduction in uncertainties of S8 over using the cosmic shear power spectra alone. The main gain from these additional probes comes through their constraining power on nuisance parameters, such as the galaxy intrinsic alignment amplitude or potential shifts in the redshift distributions, which are up to a factor of 2 better constrained compared to using cosmic shear alone, demonstrating the value of large-scale structure probe combination.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 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: 22 Jul 2020 10:03
Last Modified: 04 Sep 2021 06:57
DOI or Identification number: 10.1093/mnras/sty551
URI: https://researchonline.ljmu.ac.uk/id/eprint/13342

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