First of all, I do not have any experience with this, I am an Astronomy hobbyist at best. So I am just going to present what I found with minimal comment at this time. I found this web page that links to several programs: http://nbody.sourceforge.net/ They link to the University of Washington and their n-body shop. I don't know what your status must be to get that software (a student perhaps).
The first link also lists these sources:
Other Astrophysical N-body projects
Integration with work by others is very desirable. Here are some projects we know about. To let us know about others by submitting a new item to the SourceForge Bugs Tracker.
- The Nbody Shop - The first software released here has come from this group. The TIPSY nbody visualization program is available from this group.
- NChilada - a project to create a parallel visualization and analysis package.
- Hubble in a Bottle - a High performance parallel visualization tool. Hosted on Sourceforge.
- NEMO - a stellar dynamics toolbox.
- GADGET - a freely available parallel code for cosmological N-body/SPH simulations.
- SUNRISE - a GPL program to do radiative transfer imaging of cosmological or galactic SPH simulations.
- AMIGA - a freely available (GPL) shared memory parallel adaptive mesh code that also includes a group finder.
- astro-sim.org - a community site with pointers to astrophysical CFD and n-body codes.
Some additional links that I have found:
I hope this series of links gives you what you want.