A prescription and fast code for the long-term evolution of star
  clusters - III. Unequal masses and stellar evolution
  We present a new version of the fast star cluster evolution code Evolve Me A
Cluster of StarS (EMACSS). While previous versions of EMACSS reproduced
clusters of single-mass stars, this version models clusters with an evolving
stellar content. Stellar evolution dominates early evolution, and leads to: (1)
reduction of the mean mass of stars due to the mass loss of high-mass stars;
(2) expansion of the half-mass radius; (3) for (nearly) Roche Volume filling
clusters, the induced escape of stars. Once sufficient relaxation has occurred
(~ 10 relaxation times-scales), clusters reach a second, 'balanced' state
whereby the core releases energy as required by the cluster as a whole. In this
state: (1) stars escape due to tidal effects faster than before balanced
evolution; (2) the half-mass radius expands or contracts depending on the Roche
volume filling factor; and (3) the mean mass of stars increases due to the
preferential ejection of low-mass stars.
  We compare the EMACSS results of several cluster properties against N-body
simulations of clusters spanning a range of initial number of stars, mass,
half-mass radius, and tidal environments, and show that our prescription
accurately predicts cluster evolution for this database. Finally, we consider
applications for EMACSS, such as studies of galactic globular cluster
populations in cosmological simulations.
