Tidal Tails of Interacting Galaxies
  This paper has been withdrawn by the author. A computer simulation of two galaxies, passing in parabolic orbits, was made to show their interaction and the tidal patterns formed. The galaxies were modelled as a point masses surrounded by 5 densely packed, concentric rings of test masses in circular motion, which represented the outer disk of the galaxy. Several features were noticeable in the simulations, including: a bridge forming between the two galaxies during the interaction, mass being lost to the perturbing galaxy and universe, and an arching counterarm emanating away from the bridge. The results suggest the process was primarily kinematic. Quantitative analysis was made on the counterarm length dependence on galaxy separation and mass ratio. In both cases linear relationships were found with arm length increasing for smaller separations and for larger perturbing masses. The effects were greatly reduced in a retrograde interaction. The images were compared to astrophysical observations and qualitative features matched. 
Timothy Harrison
astro-ph.GA physics.comp-ph