A collaborative project between Vassar College and Northwestern University will be undertaken which will explore the effects of magnetic fields during close interactions between stars as are likely to take place frequently in dense stellar environments (e.g., the cores of globular clusters). Such interactions not only determine the fate of these clusters but are also believed to be the origin of exotic objects such as blue stragglers, binary pulsars, and x-ray sources. The investigators and students at Vassar will use a 3D smoothed particle hydrodynamics code developed under previous NSF funding and complete its adaptation to include magnetic fields (a 3D smoothed particle magnetohydrodynamic code). This new tool will then be used to simulate stellar collisions/mergers among a variety of types of stars (main-sequence, subgiant, red giant, and stellar remnants). Specific topics that will be addressed include stellar collisions in globular clusters (and the origins of blue stragglers, i.e., collisions versus mergers), binary mergers, and common envelope evolution. Included in this project is significant involvement by students with the goal of setting up self -sustaining student research programs (in which new students are trained by seniors). There is also the opportunity for students at either school to become involved in collaborations with students/postdoctoral fellows/faculty at the other. Likewise, useful skills in programming, modeling, hydrodynamics/fluid mechanics, etc., will be developed among the participants.
