Stellar collisions in dense stellar systems are thought to produce tell-tale “stellar exotica”, i.e. stars with a peculiar structure and evolution, like blue stragglers or very massive stars. They also influence the overall dynamics by changing the number, masses and orbits of stars. In galactic nuclei, collisional mass loss contributes to the feeding of massive black holes. Our goals are to understand and describe stellar collisions through hydrodynamical simulations and (semi)analytical calculations and to develop numerical methods to incorporate that knowledge into stellar dynamical models.
I am responsible to keep updated the site of the MODEST working group 4. MODEST is, as we define it in the web site, “a loosely knit initiative of various groups working in stellar dynamics, stellar evolution, and stellar hydrodynamics. Our aim is to provide a software framework for large-scale simulations of dense stellar systems, within which existing codes for dynamics, stellar evolution, and hydrodynamics can be easily coupled. While many of us have talked for years about combining “live” stellar evolution codes directly with N-body simulations, we have now reached a consensus between various groups about standards and interfaces, what is needed, and what is doable”.
If you are interested, please read the following pages:
- Quantities and definitions
- Role of collisions in cluster dynamics
- Tidal disruption of a star by a massive black hole
- Some youtube animations of stellar collisions