Heavy-elements heritage of the falling sky

Recent dynamical analysis based on Gaia data have revealed major accretion events in Milky Way's history. Nevertheless, our understanding of the primordial Galaxy is hindered because bona fide identification most metal-poor and correspondently oldest accreted stars remains challenging. Contrary to alpha-elements, neutron-capture elements present unexplained large abundance spreads for low metallicity stars, that could result from a mixture formation sites. We analysed abundances yttrium, europium, magnesium iron Way satellite galaxies, field halo globular clusters. The chemical information has been complemented with orbital parameters data. In particular, orbit's average inclination considered. [Y/Eu] behaviour respect [Mg/Fe] turnovers galaxies different masses reveals higher luminosity systems, which declines at metallicities, enhanced abundances, particularly [Fe/H] regime between -2.25 -1.25 dex. addition, uncovered chemo-dynamical correlation both clusters Galactic halo, accounting about half spread. under-abundances typical protracted evolutions, are preferentially observed polar-like orbits, pointing possible anisotropy processes. Our results strongly suggest spread systems masses. They also highlight nature nurture relevant formation, since its epochs, opening new pathways diagnostics building up.