Black Hole Mergers from Hierarchical Triples in Dense Star Clusters

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Documents

  • Miguel A. S. Martinez
  • Giacomo Fragione
  • Kyle Kremer
  • Sourav Chatterjee
  • Carl L. Rodriguez
  • Samsing, Johan Georg Mulvad
  • Claire S. Ye
  • Newlin C. Weatherford
  • Michael Zevin
  • Smadar Naoz
  • Frederic A. Rasio

Hierarchical triples are expected to be produced by the frequent binary-mediated interactions in the cores of globular clusters. In some of these triples, the tertiary companion can drive the inner binary to merger following large eccentricity oscillations, as a result of the eccentric Kozai-Lidov mechanism. In this paper, we study the dynamics and merger rates of black hole (BH) hierarchical triples, formed via binary-binary encounters in the CMC Cluster Catalog, a suite of cluster simulations with present-day properties representative of the Milky Way's globular clusters. We compare the properties of the mergers from triples to the other merger channels in dense star clusters, and show that triple systems do not produce significant differences in terms of mass and effective spin distribution. However, they represent an important pathway for forming eccentric mergers, which could be detected by LIGO-Virgo/Kamioka Gravitational-Wave Detector (LVK), and future missions such as LISA and the DECi-hertz Interferometer Gravitational wave Observatory. We derive a conservative lower limit for the merger rate from this channel of 0.35 Gpc(-3) yr(-1) in the local universe and up to similar to 9% of these events may have a detectable eccentricity at LVK design sensitivity. Additionally, we find that triple systems could play an important role in retaining second-generation BHs, which can later merge again in the core of the host cluster.

Original languageEnglish
Article number67
JournalAstrophysical Journal
Volume903
Issue number1
Number of pages17
ISSN0004-637X
DOIs
Publication statusPublished - 1 Nov 2020

    Research areas

  • Astrophysical black holes, Black holes, Stellar mass black holes, Gravitational wave astronomy, Gravitational wave detectors, Gravitational wave sources, Gravitational waves, Globular star clusters, Star clusters, Trinary stars, MONTE-CARLO SIMULATIONS, GRAVITATIONAL-WAVE GENERATION, KOZAI-LIDOV OSCILLATIONS, OPEN STELLAR CLUSTERS, GLOBULAR-CLUSTERS, ALGORITHMIC REGULARIZATION, CHAOTIC DYNAMICS, BINARY-BINARY, EVOLUTION, MASS

ID: 251691114