Evolution of a Virgo cluster size system in the CDM universe
with dark energy
Formation of a cluster of galaxies quite similar in size and mass to
the Virgo cluster. The region shown here is about 3 megaparsecs. Particles
show the distribution of dark matter with the brightness indicating
the local density on a logarithmic stretch. The bright clumps of particles
are the dense sites where galaxies are expected to form. Our
"camera" is tracking the progenitor of the cluster so that it is
always near the center of the field of view. The formation of objects
proceeds hierarchically in the Cold Dark Matter models. Small-mass
objects form first at z>5, they quickly grow in size and violently
merge with each other, creating increasingly larger and larger
system. This galactic "cannibalism" persists even to the present day
epoch (z=0). You see two massive objects merge at z~0.5. Note that
many of the "cannibalized" systems do not loose their identity and
become satellites orbiting in the gravitational pull of larger
systems.
Questions and comments: Andrey Kravtsov (andrey@oddjob.uchicago.edu)
You can use this material if you include the proper credit:
simulations and visualizations were performed at the Leibniz-Rechenzentrum
by
Stefan Gottloeber
(Astrophysical Institute Potsdam)