Dr. Goran Doll (UNINA & INAF-OACn)
4 March 2026
11:30, Aula Piazzi
Abstract:
We present the first systematic and comprehensive study on spectroscopic properties from UDGs and LSBs for the Hydra-I cluster of galaxies. We leverage the LEWIS (Looking into the faintEst WIth MUSE) survey and MUSE IFU spectroscopy to analyse 10 galaxies within the inner 0.4Re of the cluster, deriving stellar kinematics, integrated stellar population properties (ages, metallicities, chemical abundances) and spatially resolved metallicity, [Mg/Fe] ratios and age gradients for four of such sources. Our integrated stellar population analysis reveals that most galaxies within the cluster follow the standard mass-metallicity relationship (MZR) for dwarf galaxies, with mean metallicities of <[M/H]> ≈ 0.9 ± 0.2 dex and intermediate-to-old ages (≈ 10 Gyr). However, we find a distinct sub-population of metal-rich outliers within the core of the cluster (“early infallers”) that deviate from the standard MZR. Our two-dimensional analysis for a subset of the LEWIS sample reveals complex metallicity profiles, including flat, inverted and V-shaped. We also recover [α/Fe] gradients where we generally find strongly decreasing trends. Our results give empirical evidence for some astrophysical processes (high-spin DM halo, SN feedback) to be present in our sample, along with some evidence of environmental effects.