The Power of DESI for Photometric Redshift Calibration: A Case Study with KiDS-1000
Accurate redshift estimates are a critical requirement for weak lensing surveys and one of the main uncertainties in constraints on dark energy and large-scale cosmic structure. In this paper, we study the potential to calibrate photometric redshift (photo-z) distributions for gravitational lensing using the Dark Energy Spectroscopic Instrument (DESI). Since beginning its science operations in 2021, DESI has collected more than 50 million redshifts, adding about one million monthly. In addition to its large-scale structure samples, DESI has also acquired over 256k high-quality spectroscopic redshifts (spec-zs) in the COSMOS and XMM and VVDS fields. This is already a factor of 3 larger than previous spec-z calibration compilations in these two regions. Here, we explore calibrating photo-zs for the subset of KiDS-1000 galaxies that fall into joint self-organizing map (SOM) cells overlapping the DESI COSMOS footprint using the DESI COSMOS observations. Estimating the redshift distribution in KiDS-1000 with the new DESI data, we find broad consistency with previously published results while also detecting differences in the mean redshift in some tomographic bins with an average shifts of Delta Mean(z) = -0.028 in the mean and Delta Median(z) = +0.011 in the median across tomographic bins. However, we also find that incompleteness per SOM cell, i.e., groups of galaxies with similar colors and magnitudes, can modify n(z) distributions. Finally, we comment on the fact that larger photometric catalogs, aligned with the DESI COSMOS and DESI XMM and VVDS footprints, would be needed to fully exploit the DESI dataset and would extend the coverage to nearly eight times the area of existing 9-band photometry.
Authors
- J. Lange (ORCID: https://orcid.org/0000-0002-2450-1366)
- C. García-Quintero (ORCID: https://orcid.org/0000-0003-1481-4294)
- John E. Carlson (ORCID: https://orcid.org/0000-0001-9129-1867)
- R Keenan
- Angus H. Wright (ORCID: https://orcid.org/0000-0001-7363-7932)
- N Emas
- A. Porredon (ORCID: https://orcid.org/0000-0002-2762-2024)
- H. Hildebrandt (ORCID: https://orcid.org/0000-0002-9814-3338)
- J. McCullough (ORCID: https://orcid.org/0000-0002-4475-3456)
- Nikhil Padmanabhan (ORCID: https://orcid.org/0000-0002-2885-8602)
- Alexie Leauthaud (ORCID: https://orcid.org/0000-0002-3677-3617)
- Sven Heydenreich (ORCID: https://orcid.org/0000-0002-7273-4076)
- Michael R. Blanton (ORCID: https://orcid.org/0000-0003-1641-6222)
- Diana Blanco
- Biprateep Dey (ORCID: https://orcid.org/0000-0002-5665-7912)
- Cullen H. Blake (ORCID: https://orcid.org/0000-0002-5423-5919)
- Kyle Dawson
- Aihara Hiroaki
- M. A. G. Maia
- W. C. Brown
- John N. Bahcall
- J Ratajczak
- Darshika Ravulapalli
- Julian E. Bautista
- Jordi Miralda-Escudé
- Alex Krolewski
- Julien Guy
- Shahab Joudaki
- Xiaohui Fan
- Klaus Honscheid
- Christophe Pichon
- Andreu Font-Ribera
- Arjun Dey
- Aaron Meisner
- Rongpu Zhou
- John Peacock
- Graziano Rossi
- Martin Crocce
- Samantha Y. Skirlo
- David W. Hogg
- Gregory Tarlé
- David H. Weinberg
- Jean-Paul Kneib
- Robert C. Nichol
- Jennifer A. Tinker
- David Sprayberry
- Hu Zou
- Daniel J. Eisenstein
- David Schlegel
- Stephan J. Bailey
- John Moustakas
- Benjamin Alan Weaver
- Stephen Bailey
- Julien Delubac
- Manuel Carrasco Kind
- Christoph Saathoff
- Lily Schmassmann
- Daniel Forero-Romero
- Kyle G. Mohr
- Martin White
- Daniel Kirkby
- Christophe Yeche
Publication Details
- Journal
- The Open Journal of Astrophysics
- Published
- 2026-09-14
- DOI
- https://doi.org/10.33232/001c.163965
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- Gordon and Betty Moore Foundation
- University of California, Santa Cruz
- Ministerio de Ciencia, Innovación y Universidades
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives
- Office of Science
- Science and Technology Facilities Council
- Agencia Estatal de Investigación
- Division of Astronomical Sciences