Mocking integral field unit observations and metallicity diagnostics from cosmological simulations

¹ Institute of Astronomy, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago 7820436, Chile
² Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT, Australia
³ Nucleus Millenium ERIS, Santiago, Chile
⁴ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, F-06000 Nice, France
⁵ Instituto de Astrofísica de Andalucia, Glorieta de la Astronomía s/n, 18008 Granada, Spain
⁶ Instituto de Radioastronomía y Astrofísica (IRYA), UNAM, Campus, Morelia, Michoacán, C.P. 58089, México
⁷ Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Santiago de Chile, Chile

^⋆ Corresponding author: avcornejo@uc.cl

Received: 12 September 2024
Accepted: 27 May 2025

Abstract

Context. Hydrodynamic simulations are powerful tools for studying galaxy formation. However, it is crucial to test and improve the subgrid physics underlying these simulations by comparing their predictions with observations. To this aim, observable quantities can be derived for simulated galaxies, enabling the analysis of simulated properties through an observational approach.

Aims. Our goal is to develop a new numerical tool capable of generating synthetic emission line spectra from spatially resolved regions in simulated galaxies, carrying out mock integral field unit (IFU) observations.

Methods. We produced synthetic spectra of simulated galaxies by integrating the software CIGALE with the outcomes of hydrodynamical simulations. We considered the contributions from both stellar populations and nebular emission. The nebular emission lines in the spectra were modeled by considering only the contributions from the simulated star-forming regions. Furthermore, our model considers the properties of the surrounding interstellar medium to estimate the ionizing parameters, the metallicity, the velocity dispersion, and the electron density.

Results. We present the new numerical tool PRISMA. Leveraging synthetic spectra generated by our model, PRISMA successfully computed and recovered the intrinsic values of the star formation rate and gas-phase metallicity in local regions of simulated galaxies. Additionally, we examined the behavior of metallicity tracers, such as N2, R23, O3N2, and N2O2, recovered by PRISMA. Here, we propose new calibrations based on our simulated result. These findings show the robustness of our tool in recovering the intrinsic properties of simulated galaxies via their synthetic spectra, offering a powerful tool for confronting simulations and observational data.