Formation and Evolution of Dark Matter Halos (II.Formation of the Large-Scale Structure of the Universe) ver.2

This video focuses on the formation and evolution of the dark matter distribution from the early Universe to the present. In our Universe, small density fluctuations in the dark matter form into small clumps (called dark matter halos) through the effects of gravity. Some of these merge together to form larger halos. Within these halos, gas condenses and forms galaxies. Hundreds of galaxies gravitationally bound to each other form galaxy clusters.Galaxies and clusters are distributed in an interconnected web pattern. Such structures are called the large-scale structure of the Universe.
This video is based on a simulation taken from a suite of simulations named ν2GC (New Numerical Galaxy Catalog) . Small density fluctuations in the early Universe are represented by 8.6 billion dark matter particles. The gravitational interactions between these particles were calculated by the supercomputer ATERUI and the evolution to the present epoch was simulated. By calculating the evolution of the ingredients for stars and galaxies (called baryons) with a semi-analytic model, we can predict the distribution, evolution, and statistical properties of the galaxies and active galactic nuclei which exist in the dark matter halos. With this simulation suite, for the first time we will be able to compare simulation predictions to forthcoming state-of-the-art wide-field observations (e.g. the Subaru Telescope/HSC).

Dark matter is distributed almost uniformly in the early Universe, but small density fluctuations exist. Regions with higher density gather surrounding matter as a result of gravitational interactions and increase their density further to form halos. The initial dark matter distribution is based on state-of-the-art observational results obtained by the Planck Mission.
Many small dark matter halos are formed. Halos repeatedly merge together to form larger halos. This simulation only follows the evolution of the dark matter distribution. In the real Universe, ingredients like hydrogen and helium for the first stars and galaxies are concentrated in the centers of the halos.
This stage corresponds to the present Universe. Many large halos may host clusters or galaxies, forming large-scale structures.
Web structures connecting the groups of halos can be seen. This is the large-scale structure of the Universe.
The largest halo in this simulation is displayed. The mass is about 5x1014 solar masses, corresponds to a galactic cluster. Many small halos wander around the central halo. These are called sub-halos and thought to host member galaxies of the cluster.

Details of numerical simulation

PurposeStudying the distribution, evolution and statistical properties of dark matter, galaxies and active galactic nuclei.
20483(=8,589,934,592) dark matter particles
ComputerCray XC30 "ATERUI" (CfCA, NAOJ)
Time scale~13.8 billion years
Spatial scale~210Mpc
ResearcherTomoaki Ishiyama (Chiba University)
Reference“The ν2GC Simulations : Quantifying the Dark Side of the Universe in the Planck Cosmology”, Ishiyama, T., Enoki, M., Kobayashi, M.A.R., Makiya, R., Nagashima, M., Oogi, T.
arXiv:1412:2860, accepted by Publications of the Astronomical Society of Japan
The ν2GC Simulations (Database website)

The results of the calculation visualized in this movie were supported in part by MEXT SPIRE Field 5 and JICFuS.

YouTube for VR

Web Browsers: All directions can be seen by dragging the mouse over the YouTube screen.
Smartphones and Tablets: Using YouTube App, all directions can be seen by facing your device in your chosen direction. With VR views like Google Cardboard, you can enjoy the full effect of stereoscopic vision in all directions.
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Detail of visualization

In this movie, the number of dark matter particles has been reduced from 8.6 billion to 90 million. The 3D dome master movie was made with a technique which enables stereoscopic viewing in almost all directions. This video was produced with the 3DCG software “Maya”.
In addition, 360 degree panoramic content is also produced simultaneously. Viewing this format with a head mounted display (HMD) provides a realistic experience.


  • Simulation: Tomoaki Ishiyama
  • Visualization: Hirotaka Nakayama
  • Four-Dimensional Digital Universe Project, National Astronomical Observatory of Japan


640x360, WMV (Windows Media Video) ( zip file : 75.9 MB)

640x360, MOV (MPEG-4 Codec) ( zip file : 533 MB)

1280x720, WMV (Windows Media Video) ( zip file : 125.1 MB)

1280x720, MOV (MPEG-4 Codec) ( zip : 1.59 GB)

1920x1080, WMV (Windows Media Video) ( zip file : 145.1 MB)

1920x1080, MOV (MPEG-4 Codec) ( zip : 3 GB)

4096x2048, MP4 :360 degree panoramic video for head mounted displays. This movie file is non-stereoscopic. ( zip file : 1.56 GB)

4096x2048 (side by side) MP4 : 360 degree panoramic video for head mounted displays. This movie is stereoscopic. ( zip file : 1.56 GB)

Other file formats

  • 1920x1080 FullHD (.wmv,.mov) stereoscopic
  • 4096x4096 Dome Master (.mp4, .tif sequence files) stereoscopic/non-stereoscopic
If you want to use these file formats, please contact us.

Release date

  • 2016.07 VR version released on YouTube.
  • 2015.05 Version 2 released.
  • 2015.03 Version 1 released (only Japanese).