Movies: Galaxy Simulations & Asteroid

Here are three movies (MPEG's) that I made for my Galactic Dynamics class. I wrote the source code which generated Monte-Carlo samplings of the spatial distributions of three 10,000 identical particle Kuzmin disks. First I generated a cold razor-thin disk which was in a near-equilibrium state, and the stars had purely circular orbits in the disk. Positions and velocity components of the particles were inputted into Joshua Barnes' hierarchical N-body tree code to study the evolution of the disk over many dynamical times. The tree code employs a tree structure to calculate the gravitational force on each particle by partitioning the surrounding distribution of particles into a set of near neighbors and distant neighbors.

I then introduced random motions in an attempt to stabilize the disk against local Jeans instabilities. In the 2nd movie below you see the formation of a bar and spiral arms in the galaxy. I introduced more random motion in the 3rd movie in an attempt to satisfy the Ostriker-Peebles criterion and have a disk that is stable to the bar-instability. However, I put too much random motion into the system and my disk was not in near-equilibrium, and the stars implode during the first few dynamical times. A dark matter halo could help with this problem.

I plotted projections of the particle distributions on the galactic planes. I hope you enjoy the color!