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Formation of filaments

Formation of a group of galaxies

Formation of a galaxy

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Formation of the large-scale structure in the Universe: filaments

z=30 z=10 z=5
z=4 z=3 z=2
z=1 z=0.5 z=0

The movie stills pictured above illustrate the formation formation of clusters and large-scale filaments in the Cold Dark Matter model with dark energy. The frames show the evolution of structures in a 43 million parsecs (or 140 million light years) box from redshift of 30 to the present epoch (upper left z=30 to lower right z=0). Click to see the full-resolution version of each panel. At the initial epoch (z=30), when the age of the Universe was less than 1% of its current age, distribution of matter appears to be uniform. This is because the seed fluctuations are still fairly small. As time goes on, the fluctuations grow resulting in a wealth of structures from the smallest bright clumps which have sizes and masses similar to those of galaxies to the large filaments. Notice the filament spanning the entire box from left to right and how it becomes more and more pronounced with time. Also, note that it does not change much between z=0.5 and z=0 (i.e., the last two panels). This is because the expansion of the universe is in the stage of acceleration as the "dark energy" becomes dominant at z<1. On large scales seen here, gravity cannot compete with the dark energy-driven acceleration and the growth of structures ceases. As the contraction of large-scale structures is halted they expand with the universe and appear "frozen" in our co-moving system of coordinates.

You can download the movie as
an MPEG movie: full size (10Mb), half size (1.3Mb)

The same simulation but with a rotating box (3D geometry of the filaments can be appreciated better)
an animated gif: half size (5Mb), quarter size (1Mb)
MPEG movie: full size (9Mb) half size (1Mb)

time evolution of the large-scale structure

The same as above but in a single picture. The frames show the evolution of structures in a 43 Mpc box from redshift of 10 to the present epoch (from left to right). Click on the figure to see the full-resolution version (440k). You can download this file as a gzipped postscipt (4M) or PDF file (800k)

The Center for Cosmological Physics is a Physics Frontier Center of the National Science Foundation NSF logo

Questions and comments: Andrey Kravtsov ( )

You can use this material if you include the proper credit:
simulations were performed at the National Center for Supercomputer Applications
by Andrey Kravtsov (The University of Chicago) and Anatoly Klypin (New Mexico State University).
Visualizations by Andrey Kravtsov.