Harnois-Déraps, Joachim;
Heydenreich, Sven;
Giblin, Benjamin;
Martinet, Nicolas;
Tröster, Tilman;
Asgari, Marika;
Burger, Pierre;
... Wright, Angus H; + view all
(2024)
KiDS-1000 and DES-Y1 combined: cosmology from peak count statistics.
Monthly Notices of the Royal Astronomical Society
, 534
(4)
pp. 3305-3330.
10.1093/mnras/stae2249.
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Abstract
We analyse the fourth data release of the Kilo Degree Survey (KiDS-1000) and extract cosmological parameter constraints based on the cosmic shear peak count statistics. Peaks are identified in aperture mass maps in which the filter is maximally sensitive to angular scales in the range 2-4 arcmin, probing deep into the non-linear regime of structure formation. We interpret our results with a simulation-based inference pipeline, sampling over a broad wCDM prior volume and marginalising over uncertainties on shape calibration, photometric redshift distribution, intrinsic alignment and baryonic feedback. Our measurements constrain the structure growth parameter and the amplitude of the non-linear intrinsic alignment model to Σ8 ≡ σ8 [Ωm/0.3] 0.60 = 0.765+0.030 −0.030 and AIA = 0.71+0.42 −0.42, respectively, in agreement with previous KiDS-1000 results based on two-point shear statistics. These results are robust against modelling of the non-linear physics, different scale cuts and selections of tomographic bins. The posterior is also consistent with that from the Dark Energy Survey Year-1 peak count analysis presented in Harnois-Deraps et al (2021), and hence we jointly analyse both surveys ´ with a common pipeline. We obtain Σ joint 8 ≡ σ8 [Ωm/0.3] 0.57 = 0.759+0.020 −0.017, in agreement with the Planck wCDM results. The shear-CMB tension on this parameter increases to 3.1σ when forcing w = −1.0, and to 4.1σ if comparing instead with S joint 8,ΛCDM = 0.736+0.016 −0.018, one of the tightest constraints to date on this quantity. Residual biases in the photometric redshifts of the DES-Y1 data and in the modelling of small scales physics could lower this tension, however it is robust against other systematics. Limits in the accuracy of our emulator prevent us from constraining Ωm.
| Type: | Article |
|---|---|
| Title: | KiDS-1000 and DES-Y1 combined: cosmology from peak count statistics |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stae2249 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stae2249 |
| Language: | English |
| Additional information: | © 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | Gravitational lensing: weak – Methods: data analysis, numerical – Cosmology: dark matter, dark energy & cosmological parameters |
| 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/10199588 |
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