Post-Newtonian dynamics in dense star clusters: Formation, masses, and merger rates of highly-eccentric black hole binaries
Abstract
Using state-of-the-art dynamical simulations of globular clusters, including radiation reaction during black hole encounters and a cosmological model of star cluster formation, we create a realistic population of dynamically formed binary black hole mergers across cosmic space and time. We show that in the local universe, 10% of these binaries form as the result of gravitational-wave emission between unbound black holes during chaotic resonant encounters, with roughly half of those events having eccentricities detectable by current ground-based gravitational-wave detectors. The mergers that occur inside clusters typically have lower masses than binaries that were ejected from the cluster many Gyrs ago. Gravitational-wave captures from globular clusters contribute 1 - 2 Gpc-3 yr-1 to the binary merger rate in the local universe, increasing to ≳10 Gpc-3 yr-1 at z ∼3 . Finally, we discuss some of the technical difficulties associated with post-Newtonian scattering encounters, and how care must be taken when measuring the binary parameters during a dynamical capture.
- Publication:
-
Physical Review D
- Pub Date:
- December 2018
- DOI:
- 10.1103/PhysRevD.98.123005
- arXiv:
- arXiv:1811.04926
- Bibcode:
- 2018PhRvD..98l3005R
- Keywords:
-
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 16 Pages, 10 Figures. Accepted by Phys Rev D