https://doi.org/10.1140/epjp/s13360-023-04808-2
Regular Article
Gravitational wave signals from long-lasting binary–single black hole encounters
1
Gran Sasso Science Institute (GSSI), 67100, L’Aquila, Italy
2
INFN, Laboratori Nazionali del Gran Sasso, 67100, Assergi, Italy
3
Dipartimento di Fisica, Università di Roma La Sapienza, 00185, Rome, Italy
4
INFN, Sezione di Roma, 00185, Rome, Italy
Received:
20
November
2023
Accepted:
18
December
2023
Published online:
10
January
2024
In the dense regions of star clusters, close encounters with black holes (BHs) can occur giving rise to a new class of gravitational-wave (GW) signals. Binary–single encounters between three BHs are expected to dominate the rate of signals from unbound systems in the frequency band of terrestrial GW detectors. The encounter can describe a quasi-hyperbolic trajectory, which was the focus of a recent study. In some cases, the encounter can take a more complex form including one or two BH mergers as a result of the encounter, repeating cycles of close proximity between the BHs, and the exchange of a BH that is part of the binary. The variety of types of encounters leads to a variety of GW signals emerging from these encounters. Using the ARWV N-body code, we performed 42 numerical simulations, to explore various outcomes of binary–single interaction, and we characterize the diverse GW signatures produced during these encounters. Additionally, we evaluated the detectability of these GW signals by injecting them into the simulated noise of the Einstein Telescope and exploring different methods to detect the signals. Our findings shed light on the complexities of these interactions and their potential implications for GW astronomy.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
