The dragon-II simulations: III. Compact binary mergers in clusters with up to 1 million stars : mass, spin, eccentricity, merger rate, and pair instability supernovae rate
Compact binary mergers forming in star clusters may exhibit distinctive features that can be used to identify them among observed gravitational-wave sources. Such features likely depend on the host cluster structure and the physics of massive star evolution. Here, we dissect the population of compac...
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| Main Authors: | , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
March 2024
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| In: |
Monthly notices of the Royal Astronomical Society
Year: 2024, Volume: 528, Issue: 3, Pages: 5140-5159 |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stad3951 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1093/mnras/stad3951
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| Author Notes: | Manuel Arca sedda, Albrecht W H Kamlah, Rainer Spurzem, Francesco Paolo Rizzuto, Mirek Giersz, Thorsten Naab and Peter Berczik |
| Summary: | Compact binary mergers forming in star clusters may exhibit distinctive features that can be used to identify them among observed gravitational-wave sources. Such features likely depend on the host cluster structure and the physics of massive star evolution. Here, we dissect the population of compact binary mergers in the dragon-II simulation data base, a suite of 19 direct N-body models representing dense star clusters with up to 106 stars and < 33 per cent of stars in primordial binaries. We find a substantial population of black hole binary (BBH) mergers, some of them involving an intermediate-mass BH (IMBH), and a handful mergers involving a stellar BH and either a neutron star (NS) or a white dwarf (WD). Primordial binary mergers, ~ 30 cent of the whole population, dominate ejected mergers. Dynamical mergers, instead, dominate the population of in-cluster mergers and are systematically heavier than primordial ones. Around 20 per cent of dragon-II mergers are eccentric in the Laser Interferometer Space Antenna (LISA) band and 5 per cent in the LIGO band. We infer a mean cosmic merger rate of R ∼ 30(4.4)(1.2) yr−1 Gpc−3 for BBHs, NS–BH, and WD–BH binary mergers, respectively, and discuss the prospects for multimessenger detection of WD-BH binaries with LISA. We model the rate of pair-instability supernovae (PISNe) in star clusters and find that surveys with a limiting magnitude mbol = 25 can detect ∼1-15 yr−1 PISNe. Comparing these estimates with future observations could help to pin down the impact of massive star evolution on the mass spectrum of compact stellar objects in star clusters. |
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| Item Description: | Vorab online veröffentlicht: 2024 January 9 Gesehen am 03.07.2024 |
| Physical Description: | Online Resource |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stad3951 |