Analysis of Galaxy Formation with Hydrodynamics

We present a hydrodynamical code based on the Smooth Particle Hydrodynamics technique implemented in an AP3M code aimed at solving the hydrodynamical and gravitational equations in a cosmological frame. We analyze the ability of the code to reproduce standard tests and perform numerical simulations to study the formation of galaxies in a typical region of a CDM model. These numerical simulations include gas and dark matter particles and take into account physical processes such as shock waves, radiative cooling, and a sim-pli(cid:12)ed model of star formation. Several observed properties of normal galaxies such as Mgas=Mtotal ratios, the luminosity function and the Tully-Fisher relation are analyzed within the limits imposed by numerical resolution.