Lecture 12 Galaxy Collision Model (Midterm Projects)



Physics 141/241

Wednesday, February 22, 2006




Classical Mechanics of the galactic orbits

For the initial condition, consider to separate galaxies on parabolic collision course. Galaxy A and galaxy B do not overlap initially, and the center of masses of the individual galaxies would continue on a parabolic orbit, if the interactions of the stars would not change the picture when the galaxies begin to overlap.


mice_top.gif

First, we would like to set up the appropriate initial condition for the collision as depicted in the figure above. Notes on the algorithm are given in collision orbit note. Notes on the galaxy rotations are given in Galaxy Rotations note. Examples of initial setup from last year is given in Table of initial conditions.




Galaxy collisions in the model of Toomre&Toomre

The classic paper Galactic Bridges and Tails (Toomre&Toomre) provides a simple physical model for the understanding of galaxy collisions. We will explore four distinct collisions in the model: Mice, Antennae, Cartwheel, Milky Way. The Midterm and the Final projects will be prepared by teams. In the Midterm projects we will apply the Toomre&Toomre model to the problems. In the Final projecst the teams will run full simulations.




Preliminary team assignments:




The Mice team: Cherry, Vahid, Schatzman

Antennae team: Kelley, Traver, Lebourgeois

Cartwheel Team: Wagner, Thiemann, Miller, Golf

Milky Way Team: Noel, Clark, North







Four lab teams: