Euclid preparation. 3-dimensional galaxy clustering in configuration space. Part I. 2-point correlation function estimation
Abstract
The 2-point correlation function of the galaxy spatial distribution is a major cosmological observable that enables constraints on the dynamics and geometry of the Universe. The Euclid mission aims at performing an extensive spectroscopic survey of approximately 20--30 million H-emitting galaxies up to about redshift two. This ambitious project seeks to elucidate the nature of dark energy by mapping the 3-dimensional clustering of galaxies over a significant portion of the sky. This paper presents the methodology and software developed for estimating the 3-dimensional 2-point correlation function within the Euclid Science Ground Segment. The software is designed to overcome the significant challenges posed by the large and complex Euclid data set, which involves millions of galaxies. Key challenges include efficient pair counting, managing computational resources, and ensuring the accuracy of the correlation function estimation. The software leverages advanced algorithms, including kd-tree, octree, and linked-list data partitioning strategies, to optimise the pair-counting process. The implementation also includes parallel processing capabilities using shared-memory open multi-processing to further enhance performance and reduce computation times. Extensive validation and performance testing of the software are presented. The results indicate that the software is robust and can reliably estimate the 2-point correlation function, which is essential for deriving cosmological parameters with high precision. Furthermore, the paper discusses the expected performance of the software during different stages of the Euclid Wide Survey observations and forecasts how the precision of the correlation function measurements will improve over the mission's timeline, highlighting the software's capability to handle large data sets efficiently.
Cite
@article{arxiv.2501.16555,
title = {Euclid preparation. 3-dimensional galaxy clustering in configuration space. Part I. 2-point correlation function estimation},
author = {Euclid Collaboration and S. de la Torre and F. Marulli and E. Keihänen and A. Viitanen and M. Viel and A. Veropalumbo and E. Branchini and D. Tavagnacco and F. Rizzo and J. Valiviita and V. Lindholm and V. Allevato and G. Parimbelli and E. Sarpa and Z. Ghaffari and A. Amara and S. Andreon and N. Auricchio and C. Baccigalupi and M. Baldi and S. Bardelli and A. Basset and D. Bonino and M. Brescia and J. Brinchmann and A. Caillat and S. Camera and V. Capobianco and C. Carbone and J. Carretero and S. Casas and F. J. Castander and M. Castellano and G. Castignani and S. Cavuoti and A. Cimatti and C. Colodro-Conde and G. Congedo and C. J. Conselice and L. Conversi and Y. Copin and F. Courbin and H. M. Courtois and M. Crocce and A. Da Silva and H. Degaudenzi and G. De Lucia and A. M. Di Giorgio and J. Dinis and F. Dubath and C. A. J. Duncan and X. Dupac and S. Dusini and M. Farina and S. Farrens and F. Faustini and S. Ferriol and N. Fourmanoit and M. Frailis and E. Franceschi and P. Franzetti and M. Fumana and S. Galeotta and K. George and W. Gillard and B. Gillis and C. Giocoli and P. Gómez-Alvarez and B. R. Granett and A. Grazian and F. Grupp and L. Guzzo and S. V. H. Haugan and W. Holmes and F. Hormuth and A. Hornstrup and S. Ilić and K. Jahnke and M. Jhabvala and B. Joachimi and S. Kermiche and A. Kiessling and M. Kilbinger and B. Kubik and M. Kunz and H. Kurki-Suonio and S. Ligori and P. B. Lilje and I. Lloro and G. Mainetti and D. Maino and E. Maiorano and O. Mansutti and O. Marggraf and K. Markovic and M. Martinelli and N. Martinet and R. Massey and S. Maurogordato and E. Medinaceli and S. Mei and M. Melchior and Y. Mellier and M. Meneghetti and E. Merlin and G. Meylan and M. Moresco and B. Morin and L. Moscardini and E. Munari and C. Neissner and S. -M. Niemi and C. Padilla and S. Paltani and F. Pasian and K. Pedersen and W. J. Percival and V. Pettorino and S. Pires and G. Polenta and M. Poncet and L. Pozzetti and F. Raison and A. Renzi and J. Rhodes and G. Riccio and E. Romelli and M. Roncarelli and E. Rossetti and R. Saglia and Z. Sakr and A. G. Sánchez and D. Sapone and B. Sartoris and P. Schneider and T. Schrabback and M. Scodeggio and A. Secroun and E. Sefusatti and G. Seidel and M. Seiffert and S. Serrano and C. Sirignano and G. Sirri and L. Stanco and J. Steinwagner and C. Surace and P. Tallada-Crespí and A. N. Taylor and I. Tereno and R. Toledo-Moreo and F. Torradeflot and A. Tsyganov and I. Tutusaus and L. Valenziano and T. Vassallo and Y. Wang and J. Weller and A. Zacchei and G. Zamorani and E. Zucca and A. Biviano and M. Bolzonella and E. Bozzo and C. Burigana and M. Calabrese and D. Di Ferdinando and J. A. Escartin Vigo and R. Farinelli and F. Finelli and L. Gabarra and J. Gracia-Carpio and S. Matthew and N. Mauri and A. Mora and A. Pezzotta and M. Pöntinen and V. Scottez and P. Simon and A. Spurio Mancini and M. Tenti and M. Wiesmann and Y. Akrami and I. T. Andika and S. Anselmi and M. Archidiacono and F. Atrio-Barandela and A. Balaguera-Antolinez and D. Bertacca and M. Bethermin and A. Blanchard and L. Blot and H. Böhringer and S. Borgani and M. L. Brown and S. Bruton and R. Cabanac and A. Calabro and B. Camacho Quevedo and G. Cañas-Herrera and A. Cappi and F. Caro and C. S. Carvalho and T. Castro and K. C. Chambers and F. Cogato and S. Contarini and A. R. Cooray and O. Cucciati and S. Davini and F. De Paolis and G. Desprez and A. Díaz-Sánchez and S. Di Domizio and H. Dole and S. Escoffier and A. G. Ferrari and P. G. Ferreira and A. Finoguenov and A. Fontana and K. Ganga and J. García-Bellido and T. Gasparetto and V. Gautard and E. Gaztanaga and F. Giacomini and F. Gianotti and G. Gozaliasl and A. Gregorio and M. Guidi and C. M. Gutierrez and A. Hall and S. Hemmati and H. Hildebrandt and J. Hjorth and A. Jimenez Muñoz and S. Joudaki and J. J. E. Kajava and Y. Kang and V. Kansal and D. Karagiannis and C. C. Kirkpatrick and S. Kruk and M. Lattanzi and A. M. C. Le Brun and S. Lee and J. Le Graet and L. Legrand and M. Lembo and J. Lesgourgues and T. I. Liaudat and A. Loureiro and J. Macias-Perez and M. Magliocchetti and F. Mannucci and R. Maoli and J. Martín-Fleitas and C. J. A. P. Martins and L. Maurin and R. B. Metcalf and M. Miluzio and P. Monaco and C. Moretti and G. Morgante and C. Murray and S. Nadathur and K. Naidoo and A. Navarro-Alsina and S. Nesseris and K. Paterson and L. Patrizii and A. Pisani and V. Popa and D. Potter and P. Reimberg and I. Risso and P. -F. Rocci and M. Sahlén and A. Schneider and M. Schultheis and D. Sciotti and E. Sellentin and M. Sereno and A. Silvestri and L. C. Smith and K. Tanidis and C. Tao and N. Tessore and G. Testera and R. Teyssier and S. Toft and S. Tosi and A. Troja and M. Tucci and C. Valieri and D. Vergani and G. Verza and P. Vielzeuf and N. A. Walton},
journal= {arXiv preprint arXiv:2501.16555},
year = {2025}
}
Comments
17 pages, 13 figures, submitted to A&A