Euclid Quick Data Release (Q1). The active galaxies of Euclid
Abstract
We present a catalogue of candidate active galactic nuclei (AGN) in the Quick Release (Q1) fields. For each source we collect multi-wavelength photometry and spectroscopy information from Galaxy Evolution Explorer (GALEX), , Dark Energy Survey (DES), Wise-field Infrared Survey Explorer (WISE), , Dark Energy Survey (DESI), and Sloan Digital Sky Survey (SDSS), including spectroscopic redshift from public compilations. We investigate the AGN contents of the Q1 fields by applying selection criteria using colours and WISE-AllWISE cuts finding respectively 292,222 and 65,131 candidates. We also create a high-purity QSO catalogue based on DR3 information containing 1971 candidates. Furthermore, we utilise the collected spectroscopic information from DESI to perform broad-line and narrow-line AGN selections, leading to a total of 4392 AGN candidates in the Q1 field. We investigate and refine the Q1 probabilistic random forest QSO population, selecting a total of 180,666 candidates. Additionally, we perform SED fitting on a subset of sources with available , and by utilizing the derived AGN fraction, we identify a total of 7766 AGN candidates. We discuss purity and completeness of the selections and define two new colour selection criteria (_ and _) to improve on purity, finding 313,714 and 267,513 candidates respectively in the Q1 data. We find a total of 229,779 AGN candidates equivalent to an AGN surface density of 3641 deg for , and a subsample of 30,422 candidates corresponding to an AGN surface density of 482 deg when limiting the depth to . The surface density of AGN recovered from this work is in line with predictions based on the AGN X-ray luminosity functions.
Keywords
Cite
@article{arxiv.2503.15320,
title = {Euclid Quick Data Release (Q1). The active galaxies of Euclid},
author = {Euclid Collaboration and T. Matamoro Zatarain and S. Fotopoulou and F. Ricci and M. Bolzonella and F. La Franca and A. Viitanen and G. Zamorani and M. B. Taylor and M. Mezcua and B. Laloux and A. Bongiorno and K. Jahnke and G. Stevens and R. A. Shaw and L. Bisigello and W. Roster and Y. Fu and B. Margalef-Bentabol and A. La Marca and F. Tarsitano and A. Feltre and J. Calhau and X. Lopez Lopez and M. Scialpi and M. Salvato and V. Allevato and M. Siudek and C. Saulder and D. Vergani and M. N. Bremer and L. Wang and M. Giulietti and D. M. Alexander and D. Sluse and F. Shankar and L. Spinoglio and D. Scott and R. Shirley and H. Landt and M. Selwood and Y. Toba and P. Dayal and N. Aghanim and B. Altieri and A. Amara and S. Andreon and N. Auricchio and H. Aussel and C. Baccigalupi and M. Baldi and S. Bardelli and A. Basset and P. Battaglia and A. Biviano and A. Bonchi 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 F. J. Castander 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 M. Cropper and A. Da Silva and H. Degaudenzi and G. De Lucia and A. M. Di Giorgio and C. Dolding and H. Dole and F. Dubath and C. A. J. Duncan and X. Dupac and S. Dusini and A. Ealet and S. Escoffier and M. Fabricius and M. Farina and R. Farinelli and F. Faustini and S. Ferriol and F. Finelli and N. Fourmanoit and M. Frailis and E. Franceschi and S. Galeotta and K. George and B. Gillis and C. Giocoli and P. Gómez-Alvarez and J. Gracia-Carpio and B. R. Granett and A. Grazian and F. Grupp and S. Gwyn and S. V. H. Haugan and H. Hoekstra and W. Holmes and I. M. Hook and F. Hormuth and A. Hornstrup and P. Hudelot and M. Jhabvala and E. Keihänen and S. Kermiche and A. Kiessling and B. Kubik and M. Kümmel and M. Kunz and H. Kurki-Suonio and Q. Le Boulc'h and A. M. C. Le Brun and D. Le Mignant and P. Liebing 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 S. Marcin and O. Marggraf and M. Martinelli and N. Martinet and F. Marulli and R. Massey and D. C. Masters 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 A. Mora and M. Moresco and L. Moscardini and R. Nakajima and C. Neissner and S. -M. Niemi and J. W. Nightingale 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. A. Popa and L. Pozzetti 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 H. J. A. Rottgering and B. Rusholme and R. Saglia and Z. Sakr and A. G. Sánchez and D. Sapone and B. Sartoris and J. A. Schewtschenko and P. Schneider and T. Schrabback and M. Scodeggio and A. Secroun and G. Seidel and M. Seiffert and S. Serrano and P. Simon and C. Sirignano and G. Sirri and J. Skottfelt 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 G. Verdoes Kleijn and A. Veropalumbo and Y. Wang and J. Weller and A. Zacchei and F. M. Zerbi and I. A. Zinchenko and E. Zucca and M. Ballardini and E. Bozzo and C. Burigana and R. Cabanac and A. Cappi and D. Di Ferdinando and J. A. Escartin Vigo and G. Fabbian and L. Gabarra and J. Martín-Fleitas and S. Matthew and N. Mauri and R. B. Metcalf and A. Pezzotta and M. Pöntinen and C. Porciani and I. Risso and V. Scottez and M. Sereno and M. Tenti and M. Viel and M. Wiesmann and Y. Akrami and I. T. Andika and S. Anselmi and M. Archidiacono and F. Atrio-Barandela and C. Benoist and K. Benson and D. Bertacca and M. Bethermin and A. Blanchard and L. Blot and H. Böhringer and M. L. Brown and S. Bruton and A. Calabro and B. Camacho Quevedo and F. Caro and C. S. Carvalho and T. Castro and F. Cogato and T. Contini and A. R. Cooray and O. Cucciati and S. Davini and F. De Paolis and G. Desprez and A. Díaz-Sánchez and J. J. Diaz and S. Di Domizio and J. M. Diego and P. -A. Duc and A. Enia and Y. Fang and A. G. Ferrari and A. Finoguenov and A. Fontana and F. Fontanot and A. Franco 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 W. G. Hartley and S. Hemmati and C. Hernández-Monteagudo and H. Hildebrandt and J. Hjorth and J. J. E. Kajava and Y. Kang and V. Kansal and D. Karagiannis and K. Kiiveri and C. C. Kirkpatrick and S. Kruk and L. Legrand and M. Lembo and F. Lepori and G. Leroy and G. F. Lesci and J. Lesgourgues and L. Leuzzi and T. I. Liaudat and A. Loureiro and J. Macias-Perez and G. Maggio and M. Magliocchetti and E. A. Magnier and F. Mannucci and R. Maoli and C. J. A. P. Martins and L. Maurin and M. Miluzio and P. Monaco and C. Moretti and G. Morgante and C. Murray and K. Naidoo and A. Navarro-Alsina and S. Nesseris and F. Passalacqua and K. Paterson and L. Patrizii and A. Pisani and D. Potter and S. Quai and M. Radovich and P. -F. Rocci and G. Rodighiero and S. Sacquegna and M. Sahlén and D. B. Sanders and E. Sarpa and A. Schneider and M. Schultheis and D. Sciotti and E. Sellentin and A. Shulevski and L. C. Smith and S. A. Stanford and K. Tanidis and G. Testera and R. Teyssier and S. Tosi and A. Troja and M. Tucci and C. Valieri and A. Venhola and G. Verza and P. Vielzeuf and N. A. Walton and E. Soubrie},
journal= {arXiv preprint arXiv:2503.15320},
year = {2025}
}
Comments
Paper submitted as part of the A&A Special Issue "Euclid Quick Data Release (Q1)", 30 pages, 20 figures