The metallicity distributions of globular cluster systems in other galaxies

Although the color distributions of globular cluster systems around other galaxies are well known to be bimodal, the true metallicity distributions have been poorly defined. As part of the SLUGGS survey of nearby early-type galaxies and their globular cluster systems we have used the DEIMOS multi-object spectrograph on Keck to obtain spectra of thousands of globular clusters. We have been able to measure the strength of the near infrared calcium triplet in over 900 globular clusters in twelve galaxies. One of strongest spectral features in the optical and near infrared, the calcium triplet is sensitive to the total metallicity but not age