Binary formation within globular clusters : X-ray clues

Abstract

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 influences the relationship between the number of detected sources and the collision rate, which we find to be a power law. We also show that observing an incomplete sample provides the same results as those obtained with a complete sample. We use observations made by XMM-Newton and Chandra to constrain the formation mechanism of sources with X-ray luminosities larger than 10^{31} erg/s, and show that some of the cataclysmic variables within globular clusters should be primordial objects. We point out a possibly hidden population of neutron stars within high mass globular clusters with a low collision rate.

6 pages, no figure, accepted for publication in Astronomy & Astrophysics

References in corpus (5)

• Dynamical Formation of Close Binary Systems in Globular Clusters
• Analysis of the Quiescent Low-Mass X-ray Binary Population in Galactic Globular Clusters
• Discovery of a quiescent neutron star binary in the globular cluster M13
• An XMM-Newton observation of the globular cluster Omega Centauri
• X-ray sources and their optical counterparts in the globular cluster M 22

Cited by in corpus (1)

• The globular cluster mass/low mass X-ray binary correlation:implications for kick velocity distributions from supernovae