The miniJPAS survey. Dissecting galaxy properties across environments with spatially resolved photometry

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey ( and applied an inside-out segmentation method to investigate their star formation histories (SFHs). The stellar-population properties of these regions are derived using α, mathrm 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 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 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, 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 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: mathrm H H β, mathrm NII , and mathrm 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.