Constraining Models of Galaxy Formation with Deep Multicolor Galaxy Surveys

Abstract.

We present a comparison between the observed properties of high redshift galaxies, as they result from the analysis of deep multicolor imaging surveys, and the corresponding predictions of the latest version of CDM hierarchical model of galaxy formation. In the photometric redshift distribution of K < 21 samples only 5% of the galaxies are found at $z \ge 2$, as predicted by hierarchical scenarios where massive objects are the result of merging processes in recent epochs. Other observables - the UV luminosity density, the luminosity function and the distribution of sizes - are in broad agreement with the theoretical predictions, so that no major challenge for the CDM scenarios emerge from this comparison. However, the discrepancies observed suggest that an improvement in the knowledge and in the treatment or the physical ingredients of the models is still needed.