Milky Way-Andromeda Collision
Team
Description
Reproducibility is one of the fundamental tenets of science. For this part of the project, our goals are to test the results of a previous simulation, and do so in a reproducible manner. Along the way will deal with the realities of non-standard data formats and running unfamiliar software. All of your work will be maintained in Subversion so that you can work together, see what you've done, and to document your process and results.
The data from Dubinski, Mihos and Hernquist, 1995, is available from the NEMO N-Body Data Archive. We will use this as input to Barnes's treecode. This happens to be a more recent version of same software used originally, as detail in the numerical methods section of the paper. (In this section you can also find a time step estimate.)
Dubinski, et al., note that mass of the galaxies affects the length of tidal tails; in particular, less massive galaxies produce more dramatic tails. To test and observe this, we will run the simulation twice: once with the initial conditions we're given; and a second time with the mass of each particle reduced by half.
The simulation program is /usr/local/bin/treecode on ubuntu1 and ubuntu2.
Deliverables
- Movie of both collisions
- Plots of
- Total energy vs simulation time
- CPU time vs simulation time
- particle positions for comparison with Figure 13 Dubinski, et al.
- A Makefile that will
- run the simulations
- convert the output to VTK format
- (optional) render the images
- Commit the initial conditions, and everything necessary to reproduce the simulation (scripts, Makefile, etc.)
Instructions
- Download the initial conditions
- Write a script to change the file format to something treecode accepts
- Create a second set of inputs with the halved mass
- Write another script to convert treecode output to a VTK format
- Run the simulation
- Render the movie and plots
