We present alpha to iron abundance ratios for 226 individual red giant branch stars in nine dwarf galaxies of the Andromeda ( M 31 ) satellite system .
The abundances are measured from the combined signal of Mg , Si , Ca , and Ti lines in Keck/DEIMOS medium-resolution spectra .
This constitutes the first large sample of alpha abundance ratios measured in the M 31 satellite system .
The dwarf galaxies in our sample exhibit a variety of alpha abundance ratios , with the average values in each galaxy ranging from approximately solar ( [ \alpha / Fe ] \sim { +0.0 } ) to alpha-enhanced ( [ \alpha / Fe ] \sim { +0.5 } ) .
These variations do not show a correlation with internal kinematics , environment , or stellar density .
We confirm radial gradients in the iron abundance of two galaxies out of the five with sufficient data ( NGC 185 and And II ) .
There is only tentative evidence for an alpha abundance radial gradient in NGC 185 .
We homogeneously compare our results to the Milky Way classical dwarf spheroidals , finding evidence for wider variation in average alpha abundance .
In the absence of chemical abundances 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 and inconsistent with the Milky Way halo alpha abundance distribution even if considering only satellites with predominantly old stellar populations .
The M 31 satellite population provides a second system in which to study chemical abundances of dwarf galaxies and reveals a wider variety of abundance patterns than the Milky Way .