PRE-COLLAPSE EVOLUTION OF GALACTIC GLOBULAR-CLUSTERS

This paper is concerned with collisionless aspects of the early evolut ion of model star clusters. The effects of mass loss through stellar e volution and of a steady tidal field are modelled using N-body simulat ions. Our results (which depend on the assumed initial structure and t he mass spectrum) agree qualitatively with those of Chernoff & Weinber g, who used a Fokker-Planck model with a spherically symmetric tidal c ut-off. For those systems that are disrupted, the lifetime to disrupti on generally exceeds that found by Chernoff & Weinberg, sometimes by a s much as an order of magnitude. Because we do not model collisional e ffects correctly we cannot establish the fate of the survivors. In ter ms of theoretical interpretation, we find that tidal disruption must b e understood as a loss of equilibrium, and not a loss of stability, as is sometimes stated.