Galaxy properties in constrained realizations

Constrained Simulations of the Local Universe were made in the frame of the GIF consortium, and involved :

H. Mathis (1), G. Lemson (2), V. Springel (1), G. Kauffmann (1), S. D. M. White (1), A. Eldar (2) and A.Dekel (2)

((1) MPA Garching, (2) Hebrew University)


Running semi-analytic recipes of simple physical processes on top of the dark-matter simulation allows one to follow the formation and evolution of galaxies from high-redshift (z=10.5) to the present.

In particular, one can study evolution in the abundances, luminosities, colours and spatial distributions of specific galaxy populations, such as early-type galaxies, star-forming systems, Lyman Break galaxies, starbursts, QSO hosts or Milky Way progenitors.

A particular virtue of the constrained realisations is that the spatial and kinematic distributions of these populations can be compared in detail with those of the corresponding real galaxies in the nearby universe.


The following slides (available in .gif format) illustrate the distribution of some of these populations in our flat, low density constrained realisation (for which Omega_m=0.3, Omega_L=0.7 and h=0.7). The region shown is a slice centred on the supergalacitc plane of thickness 30 Mpc/h. The galaxy population is followed out to a distance of 80 Mpc/h from the centre.

Colour symbols represent galaxies. In each image the size and colour of the symbols encode specific astrophysical properties. Details of this encoding may be found here.

WARNING : internet transfer rates can be slow, since a single .gif file is 0.9 Mbyte on average.

Dark matter distribution

Dark matter distribution z=2.4 : gif

Dark matter distribution z=0.8 : gif

Dark matter distribution z=0. : gif

Properties at z=0.

The absolute B magnitude : gif

Location of ellipticals and S0s : gif

Galaxies in the simulation matching the PSCZ selection criterium : gif

Galaxies in the PSCZ survey having a measured B magnitude : gif

Evolution of the Star Formation Rate (SFR).

SFR at z=2.4 : gif

SFR at z=0.8 : gif

SFR at z=0. : gif

Descendants at z=0. of the z=2.4 galaxies plotted in the SFR slide : gif

QSO hosts.

QSO hosts at z=2.4 : gif

Descendants at z=0. of z=2.4 QSO hosts : gif

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Last modified: June 7, 2000. For Questions / Comments / Remarks :