| I propose to study the formation and evolution of binary white dwarf stars in dense stellar systems. These ultra-compact binary stars, which are important for a wide range of astrophysical fields, are expected to be strongly affected by stellar collisions that occur in environments of extremely high stellar number densities, such as globular star clusters. Using a complementary observational and theoretical approach I want to unravel the influence of stellar collisions by comparing the `field' population (formed without stellar collisions) with the globular cluster populations of these binaries. This forms a natural extension of my work on ultra-compact white dwarf binaries in the field. Equally importantly, it is the logical next step from recent observational and theoretical work on neutron star and black hole binaries in dense star clusters, which has shown that stellar collisions (`dynamical effects') are of crucial importance for the formation and evolution of these binaries, causing them to be highly over-abundant in dense star clusters relative to the field. To pursue this research project, I propose to go to Harvard for two years to tap into the extensive local expertise on the formation and evolution of ultra-compact binaries in globular star clusters. |
