KiDS-Legacy: Redshift distributions and their calibration

We present the redshift calibration methodology and bias estimates for the cosmic shear analysis of the fifth and final data release (DR5) of the Kilo-Degree Survey (KiDS). KiDS-DR5 includes a greatly expanded compilation of calibrating spectra, drawn from 27 square degrees of dedicated optical and near-IR imaging taken over deep spectroscopic fields. The redshift distribution calibration leverages a range of new methods and updated simulations to produce the most precise N ( z ) bias estimates used by KiDS to date. Improvements to our colour-based redshift distribution measurement method using self-organising maps (SOMs) mean that we are able to use many more sources per tomographic bin for our cosmological analyses and better estimate the representation of our source sample given the available spec- z . We validated our colour-based redshift distribution estimates with spectroscopic cross-correlations (CCs). We find that improvements to our CC redshift distribution measurement methods mean that redshift distribution biases estimated between the SOM and CC methods are fully consistent on simulations, and the data calibration is consistent to better than 2 σ in all tomographic bins.

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Publication Details

Journal
Astronomy and Astrophysics
Published
2025-10-09
DOI
https://doi.org/10.1051/0004-6361/202554909
Citations
6
Primary Topic
Astronomy and Astrophysical Research
Type
article
Field-Weighted Citation Impact
7.15
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KiDS-Legacy: Redshift distributions and their calibration

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KiDS-Legacy: Redshift distributions and their calibration

Shangrong Li, Giorgio Francesco Lesci, M. Maturi, Priyanka Jalan, Catherine Heymans, Constance Mahony, Angus H. Wright, M. Radovich, Tilman Tröster, L. Moscardini, Mijin Yoon, Maciej Bilicki, Benjamin Joachimi, Zi‐Ang Yan, Shahab Joudaki, H. Hildebrandt, Henk Hoekstra, Andrej Dvornik, Maximilian von Wietersheim-Kramsta, Christos Georgiou, Nora Elisa Chisari, Anna Wittje, Konrad H. Kuijken, Robert Reischke, Jan Luca van den Busch, Laila Linke, Lucas Porth, Marika Asgari, Benjamin Giblin, Arthur Loureiro, Yun-Hao Zhang, Anjitha John William, Benjamin Stölzner
article en
6 citations

Abstract

We present the redshift calibration methodology and bias estimates for the cosmic shear analysis of the fifth and final data release (DR5) of the Kilo-Degree Survey (KiDS). KiDS-DR5 includes a greatly expanded compilation of calibrating spectra, drawn from 27 square degrees of dedicated optical and near-IR imaging taken over deep spectroscopic fields. The redshift distribution calibration leverages a range of new methods and updated simulations to produce the most precise N ( z ) bias estimates used by KiDS to date. Improvements to our colour-based redshift distribution measurement method using self-organising maps (SOMs) mean that we are able to use many more sources per tomographic bin for our cosmological analyses and better estimate the representation of our source sample given the available spec- z . We validated our colour-based redshift distribution estimates with spectroscopic cross-correlations (CCs). We find that improvements to our CC redshift distribution measurement methods mean that redshift distribution biases estimated between the SOM and CC methods are fully consistent on simulations, and the data calibration is consistent to better than 2 σ in all tomographic bins.

Astronomy and AstrophysicsVol. 703
Leiden University (NL), University of Bonn (DE), Istituto Nazionale di Fisica Nucleare (IT), Institute for High Energy Physics (ES), Universität Innsbruck (AT), Utrecht University (NL), Heidelberg University (DE), Center for Theoretical Physics (PL), ETH Zurich (CH), University of Oxford (GB), Institute of Particle Physics (CA), Royal Observatory (GB), Instituto de Física Teórica (ES), AlbaNova (SE), Astronomical Institute of the Slovak Academy of Sciences (SK), Computational Physics (United States) (US), Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (IT), Centre for Policy Studies (IN), Osservatorio Astronomico di Padova (IT), Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (ES), Osservatorio di Astrofisica e Scienza dello Spazio, University College London (GB), Imperial College London (GB), Donostia International Physics Center (ES), Newcastle University (GB), University of Bologna (IT), University of Edinburgh (GB), Polish Academy of Sciences (PL)
Openalex Percentile: Top 3%
Astronomy and Astrophysical Research
7.15
DOIOpen Access PDFOpenAlex
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