Our project was to simulate the interaction between a dark matter halo and a satellite galaxy. The satellite was approximately the size of the LMC and the dark matter halo was meant to resemble that of the Milky Way. This project was done under the supervision of our advisor, Dr. Martin Weinberg. The bulk of the physical analysis may be found on our Results page and the details of how the whole thing was carried out may be found on our Theory page.
In particular, we wanted to observe the "wake" created in the halo by a satellite galaxy passing through the dark matter halo of its parent. Unfortunately for us, the wake is a non-trivial effect, producing fluctuations up to 20-30% from the background density field of the halo itself. The wake the satellite creates causes dynamical friction in dark matter particles. A brief discussion of dynamical friction may be found on our Theory page, also see our References page.
One of the primary motivations for this simulation was to determine whether or not such an event could be observed by astronomers. In the near future, two satellites will be launched into orbit, GAIA and SIM. GAIA will have high resolution astrometry with which it will be able to detect peculiar velocities. These peculiar velocities may reveal whether an event similar to the one we simulated has occurred in the Milky Way. SIM plans to use high accuracy interferometry to determine the velocity of 400 halo stars. This combined with its microlensing detection capabilities should allow it to see the effects of such an event as well.