AGILE: An end-to-end Rubin-LSST simulation of active galactic nuclei, galaxies, and stars

I. Software description and first data release

¹ University of Bristol, Via Frascati 33, 00078, Monteporzio Catone, Italy
² Department of Astronomy, University of Geneva, ch. d’Ecogia 16, 1290, Versoix, Switzerland
³ Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2, 00014, Helsinki, Finland
⁴ School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
⁵ INAF–Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122, Padova, Italy
⁶ Dipartimento di Fisica “Ettore Pancini”, Università degli Studi di Napoli Federico II, Via Cintia, 80126, Napoli, Italy
⁷ INAF–Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131, Napoli, Italy
⁸ School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
⁹ Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126, Pisa, Italy
¹⁰ University of Belgrade-Faculty of Mathematics, Department of Astronomy, Studentski trg 16, 11000, Belgrade, Serbia
¹¹ Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, D-21029, Hamburg, Germany
¹² Istituto Nazionale di Fisica Nucleare (INFN) – Sez. di Napoli, Compl. Univ. di Monte S. Angelo, Edificio G, Via Cinthia, I-80126, Napoli, Italy
¹³ Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Vicolo dell’Osservatorio 3, I-35122, Padova, Italy
¹⁴ Department of Physics and Astronomy “Augusto Righi”, University of Bologna, Via Gobetti 93/2, 40129, Bologna, Italy
¹⁵ Department of Physics and Astronomy, Wayne State University, Detroit, MI, 48202, USA
¹⁶ Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago, Chile
¹⁷ Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
¹⁸ Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA, 16802, USA
¹⁹ Department of Physics, 104 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
²⁰ Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
²¹ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, 100871, People’s Republic of China
²² National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing, 100101, People’s Republic of China
²³ Universidade Federal de Santa Maria (UFSM), Centro de Ciências Naturais e Exatas (CCNE), Santa Maria, 97105-900, RS, Brazil
²⁴ Eureka Scientific, 2452 Delmer Street, Suite 100, Oakland, CA, 94602-3017, USA
²⁵ Department of Physics, Yale University, PO Box 208120, New Haven, CT, 06520, USA
²⁶ INAF, Osservatorio Astrofisico di Torino, Via Osservatorio 20, I-10025, Pino Torinese, Italy
²⁷ NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
²⁸ Center for Space Science and Technology, University of Maryland Baltimore County, MD, 21250, Baltimore, USA
²⁹ Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon, 30455, Republic of Korea
³⁰ Department of Physics, Drexel University, 32 S. 32nd Street, Philadelphia, PA, 19104, USA
³¹ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstr. 1, 85748, Garching, Germany
³² Exzellenzcluster ORIGINS, Boltzmannstr. 2, D-85748, Garching, Germany
³³ Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
³⁴ Physics Department, Tor Vergata University of Rome, Via della Ricerca Scientifica 1, 00133, Rome, Italy
³⁵ INFN – Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133, Rome, Italy
³⁶ National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA, 22903, USA
³⁷ Department of Astronomy, University of Virginia, PO Box 3818, Charlottesville, VA, 22903, USA
³⁸ Department of Astronomy, University of Michigan, 1085 South University, Ann Arbor, MI, 48109, USA

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Received: 17 December 2025
Accepted: 11 March 2026

Abstract

Aims. Contemporary large-scale surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) and Euclid present an unprecedented discovery potential for studying active galactic nuclei (AGNs) at the population level in the big data era. However, one major challenge is the accurate identification and classification of AGNs from optical and near-infrared photometry or variability data alone. To optimize active galactic nucleus (AGN) selection, classification, and systematics as well as to test different data analysis tools, we present AGILE (AGNs In the LSST Era), an LSST end-to-end simulation software. Developed as part of the INAF LSST in-kind contribution, AGILE is capable of simulating the anticipated AGN population in LSST and Euclid.

Methods. We based AGILE on existing simulations of galaxies and stars, while we developed an AGN recipe based on empirical relations. AGILE populates complete galaxy samples with AGNs according to the observed AGN accretion rate distribution, and each AGN is assigned an optical/UV spectral energy distribution. Optical AGN variability is added using a damped random walk model connected to the AGN physical parameters. Finally, AGILE creates both LSST-like images and related data products.

Results. Using AGILE, we built a 24 deg² complete mock truth catalog of AGNs, galaxies, and stars with 0.2 < z < 5.5, log₁₀(M_star/M_⊙) > 8.5 (AGNs and galaxies), and r < 27.5 mag (stars). We also performed a pilot simulation (AGILE DR1) consisting of 1 deg² of LSST operations in the COSMOS field observed up to three years in accordance with the survey strategy. We used AGILE DR1 to quantify the accuracy of the LSST Science Pipelines in recovering the true fluxes of AGNs, galaxies, and stars. We quantified the LSST completeness and purity in recovering Type 1 AGNs using typical color-color and variability selections. We share the AGILE DR1 dataset, as it represents an ideal test bench for further scientific exploitation and forecasts in the context of LSST AGNs.