Cosmological simulations



Computer simulations are a powerful and important tool for understanding the cosmos. A detailed simulation can provide a means for understanding processes which occur on such long time scales (millions or even billions of years) that it is not possible to to observe these events in the universe. Cosmological simulations are used to study galaxy collisions and also the formation of large scale structure in the universe. The introductory lesson below assumes no prior background in astronomy. The advanced lesson requires experience in building computer programs from source code.

Introductory
''Note: The Galaxy Crash applet is no longer available online. See this link to download the code: http://burro.case.edu/JavaLab/''

Run the Galaxy Crash applet and try the suggestions in the Lab section.
 * Galaxy Crash "This is an interactive java applet which allows you to model galaxy collisions on your own computer. With this applet you can study how galaxies collide and merge gravitationally and how the effects of the collision depend on the properties of the galaxies. You can also recreate collisions between real interacting galaxies observed in the sky."

Another online simulation is available at Colliding Galaxies

Advanced


GADGET was developed from 2000-2005 to run cosmological simulations on massively parallel computers with distributed memory. This older software was selected for this resource due to the fact that the example programs can now be run on a typical personal computer.

GADGET-2
 * GADGET-2: A code for cosmological simulations of structure formation - Simulation code for galaxy collisions or for early structure formation in the universe.
 * Installing and Running Gadget-2
 * Running your first SPH simulation

SWIFT
 * SWIFT: SPH With Inter-dependent Fine-grained Tasking - Simulation code for galaxy collisions or for early structure formation in the universe, a drop-in replacement of GADGET-2.

Initial conditions
 * Starscream: A GPL code for galactic astronomy - Used to generate initial conditions to use with GADGET for galaxy collision simulations.

GPU version
 * cuda-gadget - "A modified version of GADGET-2 (Springel 2005) that computes tree forces on GPUs using the CUDA programming interface. Based on G2X by Carsten Frigaard." Version of GADGET-2 for GPU hardware.

Visualization
 * IFrIT: A general purpose visualization software - For viewing the results of simulations.

Other resources 
 * Data Files and Public Movies from CAST (Computational Astrophysics) group.