Are DSph Abundance Patterns Consistent with the Building Block Scenario?
During the past few years more and more detailed, high-resolution abundance analyses of individual red giants in dSphs have become available, leading to a growing, yet still limited body of knowledge about their detailed element abundance ratios. In particular, [/Fe] ratios, r- and s-process abundances are being measured. If dSphs were dominant contributors to the build-up of the Galactic halo, their abundance patterns should match those of the halo. However, the existing measurements show pronounced differences to the abundance ratios in our Galactic halo: Dwarfs are characterized by slower star formation rates, leading to reduced [/Fe] ratios at lower metallicity ([Fe/H]) than found in the Galactic halo. This can be interpreted as a signature of a larger contribution of supernovae of Type Ia early on, such that a solar [/Fe] is reached sooner (e.g., Matteucci 2003). In contrast, the Galactic halo experienced comparatively rapid star formation accompanied by gas removal, leading to lo
