Binary-binary collisions involving main-sequence stars, white dwarfs and neutron stars in globular clusters

We consider collisions between dynamically‐evolved primordial binaries consisting of main‐sequence stars, white dwarfs, and neutron stars in globular clusters. In our four‐body binary‐binary scattering experiments, we allow stars to ‘‘stick’’ if they pass close enough to each other, which leads to the formation of a wide variety of exotic objects. Most of these objects have binary companions. Also, relatively clean exchange interactions can produce binaries containing neutron stars that eventually receive material from their companions. Such systems will be observable as x‐ray binaries.