Control group of Milky Way objects with available Fe, Mg, Y, and Eu abundances. Left panel: Mg abundance with respect to iron as a function of [Fe/H] for the Milky Way sample stars with available estimates of [Y/Eu] abundance (included in the colour bar). Right panel: [Mg/Fe] as a function of [Y/Eu] the same Milky Way control group, colour coded by the [Fe/H] abundance. The linear correlations between [Mg/Fe] and [Y/Eu] in four metallicity intervals (less than [Fe/H] = −2.1 dex, between −2.1 dex and −1.5 dex, between −1.5 dex and −1.1 dex, and above [Fe/H] = −1.1 dex) are included as solid lines, following the [Fe/H] abundance colour code.