Euclid preparation. XLIX. Selecting active galactic nuclei using observed colours
Abstract
Euclid will cover over 14000 with two optical and near-infrared spectro-photometric instruments, and is expected to detect around ten million active galactic nuclei (AGN). This unique data set will make a considerable impact on our understanding of galaxy evolution and AGN. In this work we identify the best colour selection criteria for AGN, based only on Euclid photometry or including ancillary photometric observations, such as the data that will be available with the Rubin legacy survey of space and time (LSST) and observations already available from Spitzer/IRAC. The analysis is performed for unobscured AGN, obscured AGN, and composite (AGN and star-forming) objects. We make use of the spectro-photometric realisations of infrared-selected targets at all-z (SPRITZ) to create mock catalogues mimicking both the Euclid Wide Survey (EWS) and the Euclid Deep Survey (EDS). Using these catalogues we estimate the best colour selection, maximising the harmonic mean (F1) of completeness and purity. The selection of unobscured AGN in both Euclid surveys is possible with Euclid photometry alone with F1=0.22-0.23, which can increase to F1=0.43-0.38 if we limit at z>0.7. Such selection is improved once the Rubin/LSST filters (a combination of the u, g, r, or z filters) are considered, reaching F1=0.84 and 0.86 for the EDS and EWS, respectively. The combination of a Euclid colour with the [3.6]-[4.5] colour, which is possible only in the EDS, results in an F1-score of 0.59, improving the results using only Euclid filters, but worse than the selection combining Euclid and LSST. The selection of composite (=0.05-0.65 at 8-40 ) and obscured AGN is challenging, with F1<0.3 even when including ancillary data. This is driven by the similarities between the broad-band spectral energy distribution of these AGN and star-forming galaxies in the wavelength range 0.3-5 .
Cite
@article{arxiv.2409.00175,
title = {Euclid preparation. XLIX. Selecting active galactic nuclei using observed colours},
author = {Euclid Collaboration and L. Bisigello and M. Massimo and C. Tortora and S. Fotopoulou and V. Allevato and M. Bolzonella and C. Gruppioni and L. Pozzetti and G. Rodighiero and S. Serjeant and P. A. C. Cunha and L. Gabarra and A. Feltre and A. Humphrey and F. La Franca and H. Landt and F. Mannucci and I. Prandoni and M. Radovich and F. Ricci and M. Salvato and F. Shankar and D. Stern and L. Spinoglio and D. Vergani and C. Vignali and G. Zamorani and L. Y. A. Yung and S. Charlot and N. Aghanim and A. Amara and S. Andreon and N. Auricchio and M. Baldi and S. Bardelli and P. Battaglia and R. Bender and D. Bonino and E. Branchini and S. Brau-Nogue and M. Brescia and S. Camera and V. Capobianco and C. Carbone and J. Carretero and S. Casas and F. J. Castander and M. Castellano and S. Cavuoti and A. Cimatti and G. Congedo and C. J. Conselice and L. Conversi and Y. Copin and L. Corcione and F. Courbin and H. M. Courtois and M. Cropper and A. Da Silva and H. Degaudenzi and A. M. Di Giorgio and J. Dinis and X. Dupac and S. Dusini and A. Ealet and M. Farina and S. Farrens and S. Ferriol and M. Frailis and E. Franceschi and P. Franzetti and M. Fumana and S. Galeotta and B. Garilli and B. Gillis and C. Giocoli and B. R. Granett 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 E. Keihänen and S. Kermiche and A. Kiessling and M. Kilbinger and T. Kitching and M. Kümmel and M. Kunz and H. Kurki-Suonio and S. Ligori and P. B. Lilje and V. Lindholm and I. Lloro and E. Maiorano and O. Mansutti and O. Marggraf and K. Markovic and N. Martinet and F. Marulli and R. Massey and S. Maurogordato and E. Medinaceli and S. Mei and Y. Mellier and M. Meneghetti and E. Merlin and G. Meylan and M. Moresco and L. Moscardini and E. Munari and S. -M. Niemi and C. Padilla and S. Paltani and F. Pasian and K. Pedersen and W. J. Percival and V. Pettorino and G. Polenta and M. Poncet 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 D. Sapone and B. Sartoris and M. Schirmer and P. Schneider and T. Schrabback and A. Secroun and G. Seidel and S. Serrano and C. Sirignano and G. Sirri and L. Stanco and C. Surace and P. Tallada-Crespí and A. N. Taylor and I. Tereno and R. Toledo-Moreo and F. Torradeflot and I. Tutusaus and E. A. Valentijn and L. Valenziano and T. Vassallo and Y. Wang and J. Zoubian and E. Zucca and A. Biviano and E. Bozzo and C. Colodro-Conde and D. Di Ferdinando and G. Fabbian and J. Graciá-Carpio and S. Marcin and N. Mauri and Z. Sakr and V. Scottez and M. Tenti and Y. Akrami and C. Baccigalupi and M. Ballardini and M. Bethermin and A. Blanchard and S. Borgani and A. S. Borla and S. Bruton and C. Burigana and R. Cabanac and A. Calabro and A. Cappi and C. S. Carvalho and G. Castignani and T. Castro and K. C. Chambers and A. R. Cooray J. Coupon and O. Cucciati and S. Davini and G. De Lucia and G. Desprez and A. Díaz-Sánchez and S. Di Domizio and H. Dole and J. A. Escartin Vigo and S. Escoffier and I. Ferrero and F. Finelli and K. Ganga and J. García-Bellido and F. Giacomini and G. Gozaliasl and A. Gregorio and H. Hildebrandt and A. Jiminez Muñoz and J. J. E. Kajava and V. Kansal and D. Karagiannis and C. C. Kirkpatrick and L. Legrand and A. Loureiro and J. Macias-Perez and G. Maggio and M. Magliocchetti and G. Mainetti and R. Maoli and M. Martinelli and C. J. A. P. Martins and S. Matthew and L. Maurin and R. B. Metcalf and M. Migliaccio and P. Monaco and G. Morgante and S. Nadathur and L. Patrizii and V. Popa and C. Porciani and D. Potter and M. Pöntinen and P. -F. Rocci and A. G. Sánchez and A. Schneider and M. Sereno and P. Simon and J. Stadel and S. A. Stanford and J. Steinwagner and G. Testera and M. Tewes and R. Teyssier and S. Toft and S. Tosi and A. Troja and M. Tucci and J. Valiviita and M. Viel and I. A. Zinchenko},
journal= {arXiv preprint arXiv:2409.00175},
year = {2024}
}
Comments
25 pages, 28 figures, accepted for publication on A&A