Forming Globular Cluster Systems Semi-analytically
  We describe a scheme for the formation of globular cluster systems in early-type galaxies using a semi-analytic model of galaxy formation. Operating within a Lambda CDM cosmology, we assume that metal-poor globular clusters are formed at high-redshift in pre-galactic fragments, and that the subsequent gas-rich merging of these fragments leads to the formation of metal-rich clusters. We compare our results with contemporary data, and look at the particular case of the globular cluster and stellar metallicity distribution function of the nearby elliptical galaxy Centaurus A. 
M.A. Beasley, C.M. Baugh, D.A. Forbes, R.M. Sharples, C.S. Frenk