We present ages , [ Fe/H ] and abundances of the alpha elements Ca I , Si I , Ti I , Ti II , and light elements Mg I , Na I , and Al I for 31 globular clusters in M31 , which were obtained from high resolution , high signal-to-noise ratio ( SNR > 60 ) echelle spectra of their integrated light .
All abundances and ages are obtained using our original technique for high resolution integrated light abundance analysis of globular clusters .
This sample provides a never before seen picture of the chemical history of M31 .
The globular clusters are dispersed throughout the inner and outer halo , from 2.5 kpc < R _ { M 31 } < 117 kpc .
We find a range of [ Fe/H ] within 20 kpc of the center of M31 , and a constant [ Fe/H ] \sim - 1.6 for the outer halo clusters .
We find evidence for at least one massive globular cluster in M31 with an age between 1 and 5 Gyr .
The alpha-element ratios are generally similar to Milky Way globular cluster and field star ratios .
We also find chemical evidence for a late-time accretion origin for at least one cluster , which has a different abundance pattern than other clusters at similar metallicity .
We find evidence for star-to-star abundance variations in Mg , Na , and Al in the globular clusters in our sample , and find correlations of Ca , Mg , Na , and possibly Al abundance ratios with cluster luminosity and velocity dispersion , which can potentially be used to constrain globular cluster self-enrichment scenarios .
Data presented here were obtained with the HIRES echelle spectrograph on the Keck I Telescope .