High-Resolution Integrated Light Spectroscopy of Extragalactic Globular Clusters with MOOG

In this talk, I describe the tools used to analyze high-resolution integrated light (IL) spectra in MOOG. These tools require input models of the underlying stellar populations, which can be generated with photometry or with theoretical isochrones. Abundances can be determined from equivalent widths or spectrum syntheses. MOOG also has the ability to vary abundances and isotopic ratios within the underlying populations, which is a powerful tool for understanding the effects of multiple populations on IL spectra. I’ll conclude with a review of what IL spectroscopy has revealed about globular clusters in the Milky Way and M31.