Semi-Analytic Model Of Galaxy Formation

In this thesis we focus on the local galaxy formation. Based on previous work, we developed our own semi-analytic models of galaxy formation and incorporated it with a series of high-resolution N-body simulations. These high-resolution simulations enables us to model in detail the formation of the galaxy and the galaxy cluster. Currently, we pay more attention to the local universe and compare our model results with the recent observations which include the SDSS, 2dFGRS field luminosity function, the cluster luminosity function, Tully-Fisher relation, color-magnitude relation, metallicity-luminosity relation, the two points correlation function of galaxies. We found that our model can match with most of the local observations especially for the multi-wave luminosity function. Compared with other models, our model parameters are more reasonable.The two main reasons which contribute to the successful model are the inclusion of the substructures in the model and the gas cooling model for less massive halos. The model with substructures can suppress the luminous central galaxy formation in cluster and can give a better luminosity function compared with the observation. Instead of introducing much more strong feedback, the suppressing of gas cooling in small halos results in a flat faint end of the luminosity function which is in agreement with the observation. Also the reasonable model parameters, such as the metal yield and the stellar initial mass function, make it possible to re-produce the observed bimodal distribution of the color-magnitude diagram.