2025/04/03 by Cano-DÍaz, M., Rodríguez-Puebla, A., Robleto-Orús, A. C. +8 · 1 citation
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2504.02755
We derived radial profiles and inner/outer gradients of various stellar population (SP) properties for 124 bright dwarf galaxies, 107.53≤ M_*/M_\odot≤ 109.06, from the MaNDala sample, using integral field spectroscopy observations. Given the complex structure of dwarf galaxies, we used four different methods to derive SP radial profiles: two based on concentric elliptical rings, and two exploiting the spatially resolved data. For each method, we applied four approaches to calculate the inner (0 ≤ R/Re ≤ 1) and outer (0.75 ≤ R/Re ≤ 1.5) gradients of: luminosity- and mass-weighted age and stellar metallicity, dust attenuation, Dn4000 index, stellar mass and star formation rate (SFR) surface densities, and specific SFR. While the PSF has a minor impact on the SP gradients, the methodology for characterizing radial profiles significantly affects them. At fixed property, differences in inner gradients from concentric rings methods are ∼0.05-0.1 dex/Re, while outer gradients can reach 0.5-1 dex/Re, relative to the median of all gradients of that property, med(\∇ G\i). Spatially resolved methods yield smaller differences, \lesssim0.1 dex/Re. For some SP gradients, e.g. ∇SFR, the dispersion among the methods is comparable to med(\∇ G\i). While it is not possible to select a single preferred method for determining SP gradients, we suggest to use med(\∇ G\i) for each SP property. The resulting median age and metallicity suggest that, overall, bright dwarfs experienced moderate inside-out formation, and significant early SF from low-metallicity gas with outward radial migration of old SPs. The derived SP gradients provide strong constraints on feedback mechanisms in dwarf galaxies.