Early chemical enrichment of the Milky Way dwarf satellites from high-resolution and NLTE analysis of VMP stars

We present the NLTE abundances of 10 chemical species in 65 very metal-poor stars in eight dSphs and the Milky Way halo. The classical dSphs Sculptor, Ursa Minor, Sextans, and Fornax reveal a similar plateau at [alpha/Fe] = 0.3 for each of Mg, Ca, and Ti, similarly to the MW halo. We provide the evidence for a decline in alpha/Fe in the Bootes I UFD, that is probably due to the ejecta of SNeIa. The dichotomy in the [Sr/Ba] versus [Ba/H] diagram is observed in the classical dSphs, similarly to the MW halo, calling for two different nucleosynthesis channels for Sr. The Bootes I and UMa II UFDs reveal very similar ratios of [Sr/Mg] = -1.3 and [Ba/Mg] = -1. The stars in the Coma Berenices and Leo IV UFDs are even poorer in Sr and Ba. The subsolar Sr/Ba ratios of Bootes I and UMa II indicate a common r-process origin of their n-capture elements.