<i>Euclid</i>: Photometric redshift calibration performance with the clustering-redshifts technique in the Flagship 2 simulation

Aims. The precision of cosmological constraints from imaging surveys hinges on an accurately estimated redshift distribution n ( z ) of the tomographic bins, especially their mean redshifts. We assess the effectiveness of the clustering-redshifts technique in constraining Euclid tomographic redshift bins to meet the target uncertainty of σ (⟨ z ⟩) &lt; 0.002(1 + z ). We inferred these mean redshifts from the small-scale angular clustering of Euclid galaxies, which were distributed into bins with spectroscopic samples localised in narrow redshift slices. Methods. We generated spectroscopic mocks from the Flagship2 simulation for the Baryon Oscillation Spectroscopic Survey (BOSS), the Dark Energy Spectroscopic Instrument (DESI), and the Euclid Near-Infrared Spectrometer and Photometer (NISP) spectroscopic survey. We evaluated and optimised the clustering-redshifts pipeline, and we introduced a new method for measuring the photometric galaxy bias (clustering), which is the primary limitation of this technique. Results. We have successfully constrained the means and standard deviations of the redshift distributions for all of the tomographic bins (with a maximum photometric redshift of 1.6). We achieved precision beyond the required thresholds. We have identified the main sources of bias, particularly the impact of the one-halo galaxy distribution, which imposed the minimal separation scale to be larger than 1.5 Mpc for evaluating cross-correlations. These results demonstrate that clustering-redshifts can meet the precision requirements for Euclid , and we highlighted several avenues for future improvements.

Authors

Publication Details

Journal
Astronomy and Astrophysics
Published
2025-09-04
DOI
https://doi.org/10.1051/0004-6361/202555551
Citations
2
Primary Topic
Color perception and design
Type
article
Field-Weighted Citation Impact
4.88

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Euclid: Photometric redshift calibration performance with the clustering-redshifts technique in the Flagship 2 simulation

M Viel, C. Baccigalupi, S Pires, G. Seidel et al.
2 citations
Astronomy and Astrophysics
Color perception and design
4.88
article

Euclid: Photometric redshift calibration performance with the clustering-redshifts technique in the Flagship 2 simulation

M Viel, C. Baccigalupi, S Pires, G. Seidel, A. Ealet, F.J Castander, M. Martinelli, V. Lindholm, P. Tallada-Crespí, A Balestra, G. Riccio, L. Conversi, J. Martín-Fleitas, C. Sirignano, M. Brescia, E. Merlin, I. Hook, M. Eriksen, M. Kunz, G. Meylan, M. Bolzonella, J. Carretero, F. Marulli, Linda Reynolds, C. Giocoli, I. Lloro, O. Marggraf, F. Courbin, C. Valieri, Y. Copin, A. Kiessling, A. Grazian, F. Torradeflot, Angus H. Wright, F Faustini, E. Sefusatti, J Steinwagner, V. Capobianco, L. Moscardini, T. Schrabback, L. Gabarra, S. Andreon, R. Massey, S Marcin, A. Tsyganov, T. Vassallo, Benjamin Joachimi, G. Castignani, S. Paltani, R. Toledo-Moreo, M. Moresco, E. Zucca, D. Sapone, M. Meneghetti, N. Martinet, X Dupac, G. Sirri, G. Congedo, W d'Assignies, L. Valenziano, W. Holmes, S Toft, N Tessore, H. Hildebrandt, E. Romelli, Christopher J. Conselice, A. Biviano, E Medinaceli, I. Tutusaus, H. Degaudenzi, O. Mansutti, G. Zamorani, I Risso, J. Väliviita, S. Escoffier, S. Casas, C. Padilla Aranda, K. George, E. Maiorano, B. Gillis, M. Roncarelli, Marc Manera, A. Hornstrup, S. Fotopoulou, O. Ilbert, M Baldi, K. Jahnkę, B. Altieri, A. Secroun, M. Farina, M Jhabvala, F. Pasian, J. Weller, S. Ligori, M. Castellano, M Melchior, P. Fosalba, S. Galeotta, E. Franceschi, Daniel Masters, J.A Schewtschenko, L. Stanco, M. Poncet, O. Lahav, J. Gracia-Carpio, K. Markovič, S. Camera, J. Chaves-Montero, K. C. Chambers, F. Finelli⋆, R. Rébolo, E. Keihänen, B. Sartoris, P. C. Schneider, S. Cavuoti, Krishna Naidoo, N. Auricchio, M. Frailis, V Scottez, M. Fumana, A. Spurio Mancini, R. Miquel, F. Grupp, C. Carbone, H.I Teplitz, P. B. Lilje, D. Tavagnacco, M. Douspis, G. Polenta, E. Rossetti, A Renzi, C. Burigana, A.M.C Le Brun, E. Branchini, M. Kümmel, L. Pozzetti, S. Kermiche, G. De Lucia, P. Gómez-Alvarez, H. M. Courtois, W. Roster, Yun Wang, A. Da Silva, Y. W. Kang, M. D. Seiffert, Y. Mellier, D. Maino, A Amara, I. Tereno, S. de la Torre, V. Pettorino, L. A. Popa, P Battaglia, S Bardelli, H. Kurki‐Suonio, P. Hudelot, M. Crocce, Z. Sakr, J. Rhodes, C. Neissner, F. Raison, K. Pedersen, A. Cimatti, B. Kubik, G Mainetti, Y. Ascasíbar, R. Saglia, V. F. Cardone, S Mei, A. N. Taylor, S.-M. Niemi, A. Mora, S. Ferriol, D Bagot
article en
2 citations

Abstract

Aims. The precision of cosmological constraints from imaging surveys hinges on an accurately estimated redshift distribution n ( z ) of the tomographic bins, especially their mean redshifts. We assess the effectiveness of the clustering-redshifts technique in constraining Euclid tomographic redshift bins to meet the target uncertainty of σ (⟨ z ⟩) &lt; 0.002(1 + z ). We inferred these mean redshifts from the small-scale angular clustering of Euclid galaxies, which were distributed into bins with spectroscopic samples localised in narrow redshift slices. Methods. We generated spectroscopic mocks from the Flagship2 simulation for the Baryon Oscillation Spectroscopic Survey (BOSS), the Dark Energy Spectroscopic Instrument (DESI), and the Euclid Near-Infrared Spectrometer and Photometer (NISP) spectroscopic survey. We evaluated and optimised the clustering-redshifts pipeline, and we introduced a new method for measuring the photometric galaxy bias (clustering), which is the primary limitation of this technique. Results. We have successfully constrained the means and standard deviations of the redshift distributions for all of the tomographic bins (with a maximum photometric redshift of 1.6). We achieved precision beyond the required thresholds. We have identified the main sources of bias, particularly the impact of the one-halo galaxy distribution, which imposed the minimal separation scale to be larger than 1.5 Mpc for evaluating cross-correlations. These results demonstrate that clustering-redshifts can meet the precision requirements for Euclid , and we highlighted several avenues for future improvements.

Astronomy and AstrophysicsVol. 702
National Aeronautics and Space Administration, Centres de Recerca de Catalunya, European Space Agency, Generalitat de Catalunya, Magyar Tudományos Akadémia, Agenzia Spaziale Italiana, Ministerio de Ciencia e Innovación, National Astronomical Observatory of Japan, Agenția Spațială Română, Norsk Romsenter, Institut de Física d'Altes Energies, Fundação para a Ciência e a Tecnologia, Agència de Gestió d'Ajuts Universitaris i de Recerca, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Agencia Estatal de Investigación
Openalex Percentile: Top 5%
Color perception and design
4.88
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.