The formation of disk-bulge-halo systems and the origin of the Hubble sequence

摘要

We investigate the formation of disk-bulge-halo systems by including bulges in the Fall & Efstathiou theory of disks formation. This allows an investigation of bulge-dominated disk galaxies, such as SO's and disky ellipticals. These latter systems, which consist of an elliptical spheroid with an embedded disk with a scale length of typically a few hundred parsecs, seen to form a smooth sequence with spirals and SO's toward a lower disk-to-bulge ratio. The aim of this paper is to examine whether spirals, SO's, and disky ellipticals all can be incorporated in one simple galaxy-formation scenario.