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We present alpha to iron abundance ratios for 226 individual red giant branchstars in nine dwarf galaxies of the Andromeda (M 31) satellite system. Theabundances are measured from the combined signal of Mg, Si, Ca, and Ti lines inKeck/DEIMOS medium-resolution spectra. This constitutes the first large sampleof alpha abundance ratios measured in the M 31 satellite system. The dwarfgalaxies in our sample exhibit a variety of alpha abundance ratios, with theaverage values in each galaxy ranging from approximately solar ([alpha/Fe] ~+0.0) to alpha-enhanced ([alpha/Fe] ~ +0.5). These variations do not show acorrelation with internal kinematics, environment, or stellar density. Weconfirm radial gradients in the iron abundance of two galaxies out of the fivewith sufficient data (NGC 185 and And II). There is only tentative evidence foran alpha abundance radial gradient in NGC 185. We homogeneously compare ourresults to the Milky Way classical dwarf spheroidals, finding evidence forwider variation in average alpha abundance. In the absence of chemicalabundances for the M 31 stellar halo, we compare to the Milky Way stellar halo.A stellar halo comprised of disrupted M31 satellites is too metal-rich andinconsistent with the Milky Way halo alpha abundance distribution even ifconsidering only satellites with predominantly old stellar populations. The M31 satellite population provides a second system in which to study chemicalabundances of dwarf galaxies and reveals a wider variety of abundance patternsthan the Milky Way.

The Distribution of Alpha Elements in Andromeda Dwarf Galaxies