Stellar Black Hole Binary Mergers in Open Clusters
Nov 26, 201814 pages
Published in:
- Mon.Not.Roy.Astron.Soc. 483 (2019) 1, 1233-1246
- Published: Feb 11, 2019
e-Print:
- 1811.10628 [astro-ph.GA]
DOI:
- 10.1093/mnras/sty3193 (publication)
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Abstract: (Oxford University Press)
In this paper we study the evolution of a primordial black hole binary (BHB) in a sample of over 1500 direct-summation N-body simulations of small- and intermediate-size isolated star clusters as proxies of Galactic open clusters. The BHBs have masses in the range of the first LIGO/Virgo detections. Some of our models show a significant hardening of the BHB in a relatively short time. Some of them merge within the cluster, while ejected binaries, typically, have exceedingly long merger time-scales. The perturbation of stars around BHB systems is key to induce their coalescence. The BHBs which merge in the cluster could be detected with a delay of a few years between space detectors, as future LISA, and ground-based ones, due to their relatively high eccentricity. Under our assumptions, we estimate a BHB merger rate of R_mrg ∼ 2 yr^−1 Gpc^−3. We see that in many cases the BHB triggers tidal disruption events which, however, are not linked to the GW emission. Open cluster-like systems are, hence, a promising environment for GWs from BHBs and tidal disruptions.Note:
- 15 pages, 13 figures, accepted for publication in MNRAS
- black hole physics
- gravitational waves
- stars: black holes
- stars: kinematics and dynamics
- open clusters and associations: general
References(101)
Figures(22)