The miniJPAS survey

Dissecting galaxy properties across environments with spatially resolved photometry

¹ Instituto de Astrofísica de Andalucía (IAA-CSIC), P.O. Box 3004, 18080 Granada, Spain
² Departamento de Física, Universidade Federal de Santa Catarina, P.O. Box 476, 88040-900 Florianópolis, SC, Brazil
³ University of Heidelberg, Heidelberg, Germany
⁴ Instituto de Física de Cantabria (CSIC-UC), Avda. Los Castros s/n, 39005 Santander, Spain
⁵ Unidad Asociada “Grupo de Astrofísica Extragaláctica y Cosmología”, IFCA-CSIC/Universitat de València, València, Spain
⁶ Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, CEP 05508-090 São Paulo, Brazil
⁷ Observatório Nacional – MCTI (ON), Rua Gal. José Cristino 77, São Cristóvão, 20921-400 Rio de Janeiro, Brazil
⁸ Donostia International Physics Center (DIPC), Manuel Lardizabal Ibilbidea 4, San Sebastián, Spain
⁹ IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
¹⁰ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Unidad Asociada al CSIC Plaza San Juan 1, 44001 Teruel, Spain
¹¹ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan 1, 44001 Teruel, Spain
¹² Instituto de Astrofísica de Canarias (IAC), C/ Vía Láctea, S/N, E-38205 San Cristóbal de La Laguna, Tenerife, Spain
¹³ Departamento de Astrofísica, Universidad de La Laguna (ULL), Avenida Francisco Sánchez, E-38206 San Cristóbal de La Laguna, Tenerife, Spain
¹⁴ Universidade de São Paulo, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Rua do Maão 1226, 05508-090 São Paulo, Brazil
¹⁵ Instruments4, 4121 Pembury Place, La Canada Flintridge, CA 91011, USA

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Received: 18 August 2025
Accepted: 12 January 2026

Abstract

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is an ongoing observational programme aiming to map thousands of square degrees in the Northern Hemisphere. By combining 56 narrow-band photometric filters with a wide field of view, the survey delivers high-quality, integral-field-unit (IFU) like data suitable for investigating both the physical properties and the evolution of galaxies on local scales, as well as the influence of their environment. Preceding this, the miniJPAS survey observed a 1 deg² stripe using the same filter system, serving as a test bench and providing the first scientific results. In this study, we explored the spatially resolved properties of galaxies in miniJPAS and assessed the role of environment in their evolution. Our sample comprises 51 galaxies, classified by spectral type (red or blue) and environment (group or field). We employed our pipeline, Py2DJPAS, to download scientific images and catalogues, mask nearby sources, homogenise the images to the same point spread function (PSF), divide galaxies into regions, and extract their photo-spectra. To analyse the radial profiles of the galaxy properties, we used elliptical annuli in fixed steps of 0.7 R_EFF and applied an inside-out segmentation method to investigate their star formation histories (SFHs). The stellar-population properties of these regions are derived using BaySeAGal, a Bayesian parametric code for spectral-energy-distribution (SED) fitting. Additionally, we employed artificial neural networks (ANNs) to estimate the equivalent widths of the key emission lines: Hα, Hβ, [NII], and [OIII]. We find that stellar-population and emission-line properties display clear trends in a colour-mass-density diagram; redder, denser regions tend to be older and more metal-rich, and they exhibit lower specific star formation rates (sSFR), indicating a more quiescent state compared with bluer, less mass-dense regions. These latter regions also show stronger emission lines. While red and blue galaxies are distinctly separated in these diagrams, environmental classification does not produce a similarly clear separation. The radial profiles of the stellar-population properties of the galaxies are consistent with an inside-out formation scenario, based on its SFH analysis. Red and blue galaxies show distinctly different profiles, but we find no significant influence of environment on these properties. We propose that the absence of a strong environmental effect may be attributed to the relatively low stellar mass of the groups in our sample.