A simulation of galaxy formation and clustering

We discuss early results from the first N-body/hydrodynamical simulation to resolve the formation of galaxies in a volume large enough for their clust ering properties to be reliably determined. The simulation follows the form ation of galaxies by gas cooling within dark halos of mass a few times 10(1 1) M. and above, in a flat cold dark matter universe with a positive cosmol ogical constant. Over 2200 galaxies form in our simulated volume of (100 Mp c)(3). Assigning luminosities to the model galaxies using a spectral popula tion synthesis model results in a K-band luminosity function in excellent a greement with observations. The two-point correlation function of galaxies in the simulation evolves very little since z = 3, and it has a shape close to a power law over 4 orders of magnitude in amplitude. At the present day , the galaxy correlation function in the simulation is antibiased relative to the mass on small scales and unbiased on large scales. It provides a rea sonable match to observations.