Related papers: CDM, Feedback and the Hubble Sequence
A simple chemical enrichment code is described where the two basic mechanisms driving the evolution of the ages and metallicities of the stellar populations are the star formation efficiency and the fraction of gas ejected from the galaxy.…
(Abridged) The violent hierarchical nature of the LCDM cosmology poses serious difficulties for the formation of disk galaxies. To help resolve these issues, we describe a new, merger-driven scenario for the cosmological formation of disk…
We present a detailed surface density analysis of a large sample of simulated collisionless mergers of disc galaxies with bulges (mass ratios 1:1, 2:1, 3:1, 4:1, and 6:1) and without bulges (mass ratios 1:1 and 3:1). They were classified,…
We analyse N-body galaxy merger experiments involving disc galaxies. Mergers of disc-bulge-halo models are compared to those of bulge-less, disc-halo models to quantify the effects of the central bulge on the merger dynamics and on the…
Any viable cosmological framework has to match the observed proportion of early- and late-type galaxies. In this contribution, we focus on the distribution of galaxy morphological types in the standard model of cosmology (Lambda cold dark…
We study the evolution of disk galaxies within the frame of the cold dark matter (CDM) cosmologies. The hydrodynamics of a centrifugally supported gaseous disk and the growth of a stellar disk are calculated in detail taking into account…
Surveys of distant galaxies with the Hubble Space Telescope and from the ground have shown that there is only mild evolution in the relationship between radial size and stellar mass for galactic disks from z~1 to the present day. Using a…
We measure the volume luminosity density and surface luminosity density generated by the Galactic disc, using accurate data on the local luminosity function and the disc's vertical structure. From the well measured volume mass density and…
Disc dominated galaxies can be difficult to accommodate in a hierarchical formation scenario like $\Lambda$CDM, where mergers are an important growth mechanism. However, observational evidence indicates that these galaxies are common. We…
This is the summary chapter of a review book on galaxy bulges. Bulge properties and formation histories are more varied than those of ellipticals. I emphasize two advances: 1 - "Classical bulges" are observationally indistinguishable from…
(Abridged) Several aspects of the evolution of star-forming galaxies are studied using measures of the 2-dimensional surface brightness profile of a sample of 341 faint objects selected from the CFRS and LDSS redshift surveys that have been…
We present the rotation velocities V and velocity dispersions sigma along the principal axes of seven elliptical galaxies less luminous than M_B= -19.5. These kinematics extend beyond the half-light radii for all systems in this…
The mass aggregation and merger histories of present-day distinct haloes selected from the cosmological Millennium Simulations I and II are mapped into stellar mass aggregation and galaxy merger histories of central galaxies by using…
In order to understand the formation process of elliptical galaxies which are not rotationally supported, we have carried out numerical simulations of the galaxy formation from the density perturbation with a rotation corresponding to a…
We used galaxy evolutionary models in a hierarchical inside-out formation scenario to study the origin of the main properties and correlations of disk galaxies. We found that most of these properties and correlations are the result of three…
We investigate the relation between stellar mass and specific stellar angular momentum, or `Fall relation', for a sample of 17 isolated, regularly rotating disc galaxies at z=1. All galaxies have a) rotation curves determined from Halpha…
We compare the central mass concentration of Cold Dark Matter halos found in cosmological N-body simulations with constraints derived from the Milky Way disk dynamics and from the Tully-Fisher relation. For currently favored values of the…
New simulations are presented which investigate the formation of smaller groups of galaxies in a CDM like universe. The simulations follow the evolution of dark matter and gas and are performed with an SPH code adapted for the…
The formation and evolution of galactic disks is particularly important for understanding how galaxies form and evolve, and the cause of the variety in which they appear to us. Ongoing large surveys, made possible by new instrumentation at…
We investigate detailed kinematical properties of simulated collisionless merger remnants of disk galaxies with mass ratios of 1:1 and 3:1. The simulations were performed by direct summation using the new special hardware device GRAPE-5. In…