Euclid preparation. Estimating galaxy physical properties using CatBoost chained regressors with attention
Abstract
Euclid will image ~14000 deg^2 of the extragalactic sky at visible and NIR wavelengths, providing a dataset of unprecedented size and richness that will facilitate a multitude of studies into the evolution of galaxies. In the vast majority of cases the main source of information will come from broad-band images and data products thereof. Therefore, there is a pressing need to identify or develop scalable yet reliable methodologies to estimate the redshift and physical properties of galaxies using broad-band photometry from Euclid, optionally including ground-based optical photometry also. To address this need, we present a novel method to estimate the redshift, stellar mass, star-formation rate, specific star-formation rate, E(B-V), and age of galaxies, using mock Euclid and ground-based photometry. The main novelty of our property-estimation pipeline is its use of the CatBoost implementation of gradient-boosted regression-trees, together with chained regression and an intelligent, automatic optimization of the training data. The pipeline also includes a computationally-efficient method to estimate prediction uncertainties, and, in the absence of ground-truth labels, provides accurate predictions for metrics of model performance up to z~2. We apply our pipeline to several datasets consisting of mock Euclid broad-band photometry and mock ground-based ugriz photometry, to evaluate the performance of our methodology for estimating the redshift and physical properties of galaxies detected in the Euclid Wide Survey. The quality of our photometric redshift and physical property estimates are highly competitive overall, validating our modeling approach. We find that the inclusion of ground-based optical photometry significantly improves the quality of the property estimation, highlighting the importance of combining Euclid data with ancillary ground-based optical data. (Abridged)
Keywords
Cite
@article{arxiv.2504.13020,
title = {Euclid preparation. Estimating galaxy physical properties using CatBoost chained regressors with attention},
author = {Euclid Collaboration and A. Humphrey and P. A. C. Cunha and L. Bisigello and C. Tortora and M. Bolzonella and L. Pozzetti and M. Baes and B. R. Granett and A. Amara and S. Andreon and N. Auricchio and C. Baccigalupi and M. Baldi and S. Bardelli and A. Biviano and C. Bodendorf and D. Bonino and E. Branchini and M. Brescia and J. Brinchmann and S. Camera and G. Cañas-Herrera and V. Capobianco and C. Carbone and J. Carretero and S. Casas and M. Castellano and G. Castignani and S. Cavuoti and K. C. Chambers 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 A. Da Silva and H. Degaudenzi and G. De Lucia and J. Dinis and F. Dubath and X. Dupac and S. Dusini and S. Escoffier and M. Farina and R. Farinelli and S. Farrens and S. Ferriol and M. Frailis and E. Franceschi and S. Galeotta and K. George and B. Gillis and C. Giocoli and A. Grazian and F. Grupp and L. Guzzo and S. V. H. Haugan and W. Holmes and I. Hook and F. Hormuth and A. Hornstrup and K. Jahnke and B. Joachimi and E. Keihänen and S. Kermiche and A. Kiessling and M. Kilbinger and B. Kubik and M. Kümmel and M. Kunz and H. Kurki-Suonio and S. Ligori and P. B. Lilje and V. Lindholm 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 F. Marulli and R. Massey and H. J. McCracken 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 L. Moscardini and E. Munari and R. Nakajima and S. -M. Niemi and J. W. Nightingale and C. Padilla and S. Paltani and F. Pasian and K. Pedersen and V. Pettorino and S. Pires and G. Polenta and M. Poncet and L. A. Popa and F. Raison and R. Rebolo 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 R. Scaramella and P. Schneider and T. Schrabback and M. Scodeggio and A. Secroun and E. Sefusatti and G. Seidel and S. Serrano and P. Simon and C. Sirignano and A. Spurio Mancini and L. Stanco and J. Steinwagner and P. Tallada-Crespí and A. N. Taylor and I. Tereno and S. Toft and R. Toledo-Moreo and F. Torradeflot and I. Tutusaus and L. Valenziano and J. Valiviita and T. Vassallo and A. Veropalumbo and Y. Wang and J. Weller and G. Zamorani and J. Zoubian and E. Zucca and A. Boucaud and E. Bozzo and C. Burigana and M. Calabrese and N. Mauri and V. Scottez and M. Tenti and M. Viel and M. Wiesmann and Y. Akrami and V. Allevato and S. Anselmi and M. Ballardini and A. Blanchard and S. Borgani and S. Bruton and R. Cabanac and A. Calabro and A. Cappi and C. S. Carvalho and T. Castro and S. Contarini and A. R. Cooray and J. Coupon and O. Cucciati and G. Desprez and A. Díaz-Sánchez and S. Di Domizio and J. A. Escartin Vigo and A. G. Ferrari and P. G. Ferreira and I. Ferrero and F. Fornari and L. Gabarra and K. Ganga and J. García-Bellido and E. Gaztanaga and F. Giacomini and G. Gozaliasl and A. Gregorio and A. Hall and H. Hildebrandt and J. Hjorth and J. J. E. Kajava and V. Kansal and D. Karagiannis and C. C. Kirkpatrick and L. Legrand and G. Libet and A. Loureiro and G. Maggio and M. Magliocchetti and F. Mannucci and R. Maoli and C. J. A. P. Martins and S. Matthew and L. Maurin and R. B. Metcalf and P. Monaco and C. Moretti and G. Morgante and Nicholas A. Walton and J. Odier and L. Patrizii and M. Pöntinen and V. Popa and C. Porciani and D. Potter and I. Risso and P. -F. Rocci and M. Sahlén and A. Schneider and M. Sereno and C. Tao and G. Testera and R. Teyssier and S. Tosi and A. Troja and M. Tucci and C. Valieri and D. Vergani and G. Verza},
journal= {arXiv preprint arXiv:2504.13020},
year = {2025}
}
Comments
22 pages, 13 figures, 4 tables. Accepted for publication by Astronomy & Astrophysics