3×2pt cosmology with KiDS-1000, BOSS and 2dFLenS:

The 3×2pt analysis of KiDS-1000 with BOSS and 2dFLenS is presented in Heymans, Tröster et al 2021 with the underlying methodology detailed in Joachimi, Lin, Asgari, Tröster, Heymans et al 2021.

Paper

KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints

Catherine Heymans, Tilman Tröster, Marika Asgari, Chris Blake, Hendrik Hildebrandt, Benjamin Joachimi, Konrad Kuijken, Chieh-An Lin, Ariel G. S├ínchez, Jan Luca van den Busch, Angus H. Wright, Alexandra Amon, Maciej Bilicki, Jelte de Jong, Martin Crocce, Andrej Dvornik, Thomas Erben, Maria Cristina Fortuna, Fedor Getman, Benjamin Giblin, Karl Glazebrook, Henk Hoekstra, Shahab Joudaki, Arun Kannawadi, Fabian Köhlinger, Chris Lidman, Lance Miller, Nicola R. Napolitano, David Parkinson, Peter Schneider, HuanYuan Shan, Edwin A. Valentijn, Gijs Verdoes Kleijn, and Christian Wolf

We present a joint cosmological analysis of weak gravitational lensing observations from the Kilo-Degree Survey (KiDS-1000), with redshift-space galaxy clustering observations from the Baryon Oscillation Spectroscopic Survey (BOSS), and galaxy-galaxy lensing observations from the overlap between KiDS-1000, BOSS and the spectroscopic 2-degree Field Lensing Survey (2dFLenS). This combination of large-scale structure probes breaks the degeneracies between cosmological parameters for individual observables, resulting in a constraint on the structure growth parameter S88m/0.3)0.5=0.766+0.020-0.014, that has the same overall precision as that reported by the full-sky cosmic microwave background observations from Planck. The recovered S8 amplitude is low, however, by 8.3±2.6% relative to Planck. This result builds from a series of KiDS-1000 analyses where we validate our methodology with variable depth mock galaxy surveys, our lensing calibration with image simulations and null-tests, and our optical-to-near-infrared redshift calibration with multi-band mock catalogues and a spectroscopic-photometric clustering analysis. The systematic uncertainties identified by these analyses are folded through as nuisance parameters in our cosmological analysis. Inspecting the offset between the marginalised posterior distributions, we find that the S8-difference with Planck is driven by a tension in the matter fluctuation amplitude parameter, σ8. We quantify the level of agreement between the CMB and our large-scale structure constraints using a series of different metrics, finding differences with a significance ranging between ∼3σ, when considering the offset in S8, and ∼2σ, when considering the full multi-dimensional parameter space.

Fiducial Results

The marginalised posterior distribution in the σ8m plane, comparing the 3×2pt analyses from KiDS-1000 with BOSS and 2dFLenS, with the 3×2pt analysis from DES Y1 (Abbott et al. 2018), and the CMB constraints from Planck Collaboration et al. (2020). The KiDS-1000 3×2pt result can also be compared to our previous KV450-BOSS analysis from Tröster et al 2020.

Heymans et al 2021

Download the Data products

The data products used to produce the figure above can be downloaded as a tarball. The tarball includes the sampled posteriors in the form of Multinest chains, for the KiDS-1000 bandpower cosmic shear analysis, the BOSS-DR12 galaxy clustering analysis, different 2×2pt combinations and the fiducial 3×2pt analysis (see the README). You can download the 3×2pt data vectors, covariance matrices and the redshift distribution of galaxies from our open source software and data repository.

Contacts

Any questions? Please contact Catherine Heymans (heymans[at]roe.ac.uk) and Tilman Tröster (ttr[at]roe.ac.uk)

Acknowledgment

We welcome independent analyses of the KiDS-1000 data products, provided that KiDS is acknowledged in any resulting publications. Users of these data are required to include the following statement in their paper:

Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 177.A-3016, 177.A-3017, 177.A-3018 and 179.A-2004, and on data products produced by the KiDS consortium. The KiDS production team acknowledges support from: Deutsche Forschungsgemeinschaft, ERC, NOVA and NWO-M grants; Target; the University of Padova, and the University Federico II (Naples).

Additionally, any publications should cite the relevant KiDS-1000 papers as follows:

We use the gold sample of weak lensing and photometric redshift measurements from the fourth data release of the Kilo-Degree Survey (Kuijken et al. 2019, Wright et al. 2020, Hildebrandt et al. 2021, Giblin et al 2021), hereafter referred to as KiDS-1000. Cosmological parameter constraints from KiDS-1000 have been presented in Asgari et al 2021 (cosmic shear), Heymans et al 2021 (3x2pt) and Tröster et al 2021 (beyond ΛCDM), with the methodology presented in Joachimi et al 2021.