We have performed TreeSPH simulations of galaxy formation in a standard ΛCDM cosmology, including effects of star formation,
energetic stellar feedback processes and a meta-galactic UV field, and obtain a mix of disk, lenticular and elliptical galaxies.
The disk galaxies are deficient in angular momentum by only about a factor of two compared to observed disk galaxies. The
stellar disks have approximately exponential surface density profiles, and those of the bulges range from exponential to
r
1/4, as observed. The bulge-to-disk ratios of the disk galaxies are consistent with observations and likewise are their integrated
B-V colours, which have been calculated using stellar population synthesis techniques. Furthermore, we can match the observed
I-band Tully-Fisher (TF) relation, provided that the mass-to-light ratio of disk galaxies is
(M/L
I) ≃ 0.6–0.7. The ellipticals and lenticulars have approximately
r
1/4 stellar surface density profiles, are dominated by non-disklike kinematics and flattened due to non-isotropic stellar velocity
distributions, again consistent with observations.
Cosmology - galaxy formation - numerical methods
This revised version was published online in September 2006 with corrections to the Cover Date.