The spatial variations of stellar population properties within a galaxy are intimately related to their formation process. Therefore, spatially resolved studies of galaxies are essential to uncover their formation and assembly. The Javalambre Photome
tric Local Universe Survey (J-PLUS) is a dedicated multi-filter designed to observed ~8500 deg2 using twelve narrow-, intermediate- and broad-band filters in the optical range. In this study, we test the potential of the multi-filter observation carried out with J-PLUS to investigate the properties of spatially-resolved nearby galaxies. We present detailed 2D maps of stellar population properties (age, metallicity, extinction, and stellar mass surface density) for two early-type galaxies observed in both, J-PLUS and CALIFA surveys: NGC 5473 and NGC 5485. Radial structures are also compared and luminosity- and mass-weighted profiles are derived. We use MUFFIT to process the J-PLUS observations, and two different techniques (STARLIGHT and STECKMAP) to analyze IFU CALIFA data. We demonstrate that this novel technique delivers radial stellar population gradients in good agreement with the IFU technique CALIFA/STECKMAP although comparison of the absolute values reveals the existence of intrinsic systematic differences. Radial stellar population gradients differ when CALIFA/STARLIGHT methodology is used. Age and metallicity radial profiles derived from J-PLUS/MUFFIT are very similar when luminosity- or mass-weighted properties are used, suggesting that the contribution of a younger component is small. Comparison between the three methodologies reveals some discrepancies suggesting that the specific characteristics of each method causes important differences. We conclude that the ages, metallicities and extinction derived for individual galaxies not only depend on the chosen models but also depend on the method used.
We present a technique that permits the analysis of stellar population gradients in a relatively low cost way compared to IFU surveys analyzing a vastly larger samples as well as out to larger radii. We developed a technique to analyze unresolved ste
llar populations of spatially resolved galaxies based on photometric multi-filter surveys. We derived spatially resolved stellar population properties and radial gradients by applying a Centroidal Voronoi Tesselation and performing a multi-color photometry SED fitting. This technique has been applied to a sample of 29 massive (M$_{star}$ > 10$^{10.5}$ M$_{odot}$), early-type galaxies at $z$ < 0.3 from the ALHAMBRA survey. We produced detailed 2D maps of stellar population properties (age, metallicity and extinction). Radial structures have been studied and luminosity-weighted and mass-weighted gradients have been derived out to 2 - 3.5 R$_mathrm{eff}$. We find the gradients of early-type galaxies to be on average flat in age ($ abla$log Age$_mathrm{L}$ = 0.02 $pm$ 0.06 dex/R$_mathrm{eff})$ and negative in metallicity ($ abla$[Fe/H]$_mathrm{L}$ = - 0.09 $pm$ 0.06 dex/R$_mathrm{eff}$). Overall, the extinction gradients are flat ($ abla$A$_mathrm{v}$ = - 0.03 $pm$ 0.09 mag/R$_mathrm{eff}$ ) with a wide spread. These results are in agreement with previous studies that used standard long-slit spectroscopy as well as with the most recent integral field unit (IFU) studies. According to recent simulations, these results are consistent with a scenario where early-type galaxies were formed through major mergers and where their final gradients are driven by the older ages and higher metallicity of the accreted systems. We demonstrate the scientific potential of multi-filter photometry to explore the spatially resolved stellar populations of local galaxies and confirm previous spectroscopic trends from a complementary technique.
