The Globular Cluster System of M87

We have begun a program with the Low Resolution Imaging Spectrograph, operating with 30 multi-slits per exposure (Oke et al 1994, Cohen et al 1993) on the ten-meter W. M. Keck telescope located on Mauna Kea, Hawaii to observe the globular cluster systems of the Virgo ellipticals. We expect to learn about the dark matter content of galaxy halos, the formation of these halos and their cluster systems, possibly the formation of the galaxy’s themselves, the interaction of the cluster system with the galaxy’s gravitational potential (i.e. rotation and spinup), and the homogeneity of chemical evolution in various places. The metallicity of the globular clusters versus the metallicity of the underlying galaxy can also by analyzed. In addition the dynamics (i.e. in practice, the rotation and velocity dispersion) of the halo of the parent galaxy versus the globular cluster system can be determined