Semi-analytic modelling of galaxy formation: the local Universe

Using semi-analytic models of galaxy formation, we investigate galaxy prope rties such as the Tully-Fisher relation, the B- and K-band LFs, cold gas co ntents, sizes, metallicities and colours, and compare our results with obse rvations of local galaxies. We investigate several different recipes for st ar formation and supernova feedback, including choices that are similar to the treatment by Kauffmann, White & Guiderdoni and Cole et al., as well as some new recipes. We obtain good agreement with all of the key local observ ations mentioned above. In particular, in our best models, we simultaneousl y produce good agreement with both the observed B- and K-band LFs and the I -band Tully-Fisher relation. Improved cooling and supernova feedback modell ing, inclusion of dust extinction and an improved Press-Schechter model all contribute to this success. We present results for several variants of the CDM family of cosmologies, and find that models with values of Omega(0) si milar or equal to 0.3-0.5 give the best agreement with observations.