Binary globular clusters

Formation of Binary Pulsars in Globular Clusters

Close to 70 radio pulsars have now been discovered in 23 globular clusters, with a record 22 pulsars observed in 47 Tuc alone. Accurate timing solutions, including positions in the cluster, are known for many of the pulsars. These recent observations provide a unique opportunity to re-examine theoretically the formation and evolution of recycled pulsars in globular clusters. This brief review f...

Searches for Binary Stars in Globular Clusters

The Orbital Eccentricities of Binary Millisecond Pulsars in Globular Clusters

Low-mass binary millisecond pulsars (LMBPs) are born with very small orbital eccentricities, typically of order e i 10 ?6 {10 ?3. In globular clusters, however, higher eccentricities e f e i can be induced by dynamical interactions with passing stars. Here we show that the cross section for this process is much larger than previously estimated. This is because, even for initially circular binar...

The Evolution of Binary Fractions in Globular Clusters

We study the evolution of binary stars in globular clusters using a new Monte Carlo approach combining a population synthesis code (StarTrack), and a simple treatment of dynamical interactions in the dense cluster core using a new tool for computing 3-body and 4-body interactions (Fewbody). We find that the combination of stellar evolution and dynamical interactions (binary–single and binary–bi...

Binary formation within globular clusters : X-ray clues

We have investigated the effect of the number of primordial binaries on the relationship between the total number of detected binaries within globular cluster and its collision rate. We have used simulated populations of binary stars in globular clusters : primordial binaries and binaries formed through gravitational interactions. We show that the initial number of primordial binaries influence...