Cluster cores are rich of red and old galaxies, which contain the fossil imprints of their formation and evolution mechanisms in their stellar metallicity gradients. By taking advantage of an exquisite coupling of HST and deep MUSE observations we characterised the spectroscopic properties of 272 early-type galaxies in the cores of 12 galaxy clusters at redshifts ranging from z∼0.3 up to z∼0.5. The favourable combination of the redshift of the clusters with the angular extension and spatial resolution of the MUSE mosaics allowed us to directly measure the stellar age and metallicity gradients at unprecedented galactocentric distances (for a spectroscopic analysis). This is usually not that simple at such redshifts, due to the poor radial coverage we are limited to when observing the stellar continuum of individual distant galaxies. Consistently with previous findings, our results confirm a strong and negative mean stellar metallicity gradient and a negligible mean stellar age gradient. Various correlations have been also tested. We found the strong dependence to be the one on the velocity dispersion, with a downturn of the stellar metallicity gradient for the most massive galaxies in our sample, in agreement with a merging scenario.
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