A Galaxy Spiral Arm Formation

Simulation: Elena D’Onghia and Mark Vogelsberger Harvard FAS Supercomputer Odyssey Visualization: Thiago ize Scientific Computing and Imaging (SCI) Institute - University of Utah Rendering of spiral arm formation consisting of 512 time steps of 100 million particles (stars) per time step. Rendered using the Manta Interactive Ray Tracer by making each particle a transparent sphere with transparency decreasing with increasing galaxy radius. Color map corresponds to particle speed. We visualize a time varying simulation of spiral arm formation. There are 512 time steps, each of which contains 100 million particles produced by a Monte Carlo N-body method. Traditionally, this is rendered by creating a density field from the particles and then rendering the volume. However, we rendered this video by directly ray tracing the particles using the Manta Interactive Ray Tracer. Each particle is made transparent, with transparency decreasing as particles move further away from the galaxy center. The variable transparency allows for the spiral structure to be easily observed. The color map corresponds to particle speed.