We present global metallicity properties , metallicity distribution functions ( MDFs ) and radial metallicity profiles for the six most luminous M31 dwarf galaxy satellites : M32 , NGC 205 , NGC 185 , NGC 147 , Andromeda VII , and Andromeda II .
The results presented are the first spectroscopic MDFs for dwarf systems surrounding a host galaxy other than the Milky Way .
Our sample consists of individual metallicity measurements for 1243 red giant branch ( RGB ) member stars spread across these six systems .
We determine metallicities based on the strength of the Ca ii triplet lines using the empirical calibration of Carrera et al .
( 2013 ) which is calibrated over the metallicity range -4 < [ Fe/H ] < +0.5 .
We find that these M31 satellites lie on the same luminosity-metallicity relationship as the Milky Way dwarf satellites .
We do not find a trend between the internal metallicity spread and galaxy luminosity , contrary to previous studies .
The MDF widths of And II and And VII are similar to the MW dwarfs of comparable luminosity , however , our four brightest M31 dwarf are more luminous than any of the MW dwarf spheroidals and have broader MDFs .
The MDFs of our six M31 dwarfs are consistent with the leaky box model of chemical evolution , although our metallicity errors allow a wide range of evolution models .
We find a significant radial gradient in metallicity in only two of our six systems , NGC 185 and Andromeda II , and flat radial metallicity gradients in the rest of our sample with no observed correlation between rotational support and radial metallicity gradients .
While the average properties and radial trends of the M31 dwarf galaxies agree with MW counterparts at similar luminosity , the detailed MDFs are different , particularly at the metal-rich end .