UCL Discovery Stage
UCL home » Library Services » Electronic resources » UCL Discovery Stage

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

Heymans, C; Tröster, T; (2020) KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints. Astronomy & Astrophysics 10.1051/0004-6361/202039063. (In press). Green open access

[thumbnail of aa39063-20.pdf]
Preview
Text
aa39063-20.pdf - Published Version

Download (4MB) | Preview

Abstract

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 S 8 = σ8 √ Ωm/0.3 = 0.766+0.020 −0.014, which has the same overall precision as that reported by the full-sky cosmic microwave background observations from Planck. The recovered S 8 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 S 8-difference with Planck is driven by a tension in the matter fluctuation amplitude parameter, σ8. We quantify the level of agreement between the cosmic microwave background 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 S 8, and ∼2σ, when considering the full multi-dimensional parameter space.

Type: Article
Title: KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
Open access status: An open access version is available from UCL Discovery
DOI: 10.1051/0004-6361/202039063
Publisher version: https://doi.org/10.1051/0004-6361/202039063
Language: English
Additional information: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: gravitational lensing: weak, methods: data analysis, methods: statistical, surveys, cosmology: observations
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-pp.ucl.ac.uk/id/eprint/10116563
Downloads since deposit
1,152Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item