Observational evidence for origin of stellar exotica in globular clusters
Abstract
The formation of special binaries in a globular cluster is regulated by the total encounter rate γ in the cluster, but their life expectancy by the number of encounters γ that one system experiences. The orbital periods indicate whether a neutron star or white dwarf entered a binary via direct collision, via tidal capture, or via exchange encounter. The numbers of X-ray binaries with a neutron star scales with γ. Magnetically active binaries (including blue stragglers) are formed via evolution of primordial binaries, and their numbers scale with the cluster mass. Cataclysmic variables are formed by stellar encounters or via evolution of a primordial binary in clusters with high and low central density, respectively.
- Publication:
-
Highlights of Astronomy
- Pub Date:
- August 2007
- DOI:
- 10.1017/S1743921307011271
- Bibcode:
- 2007HiA....14..440V
- Keywords:
-
- globular clusters;
- binaries;
- X-rays: binaries