Eccentricity and Inclination Excitation of Stellar Orbits around Merging Black Hole Binaries
- 1Nanjing University
Abstract
Identifying the formation channels of merging compact-object binaries remains a fundamental challenge in gravitational-wave (GW) astrophysics. Here we formulate a generalized framework incorporating both third-body perturbations and post-Newtonian effects to investigate the resonance-driven excitation of eccentricity and/or inclination for stellar orbits around merging black hole binaries (BHBs). We show that, at the quadrupole level, inclination excitation is driven by adiabatic capture into a quadrupole-order resonance, with subsequent resonance escape governed by the conservation of phase-space area. Furthermore, in the coplanar octupole regime, an apsidal precession resonance triggers robust eccentricity growth, where the capture probability depends on the initial conditions. For spatial octupole configurations, we reveal a distinct two-stage evolutionary pathway: the quadrupole-order resonance first excites the orbital inclination, followed by subsequent eccentricity growth driven by the inverse von Zeipel–Lidov–Kozai (ZLK) resonance. Our results indicate that these resonance-driven dynamics could imprint observable kinematic signatures on surrounding stellar populations, thereby offering a novel indirect probe for merging BHBs.
Related
- Limits on eccentricity excitation by tidally enhanced mass loss in Wolf-Rayet binaries
- Numerical estimation of the capture ability of Neptunian mean motion resonances II. Influence of eccentricity and inclination
- The Influence of the Inclination of the Accretion Disk in Black Hole X-Ray Binaries on the Energy Spectrum Characteristics
- Compactness Peaks and Subpopulations: Probing Stellar Physics and Formation Channels of Merging Binary Black Holes
- Dynamical formation of high-eccentricity compact binaries through BH--BH*/TZO collisions
BibTeX
@article{gao2026eccentricity,
title = {{Eccentricity and Inclination Excitation of Stellar Orbits around Merging Black Hole Binaries}},
author = {Hao Gao and Hanlun Lei},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/aeab83},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aeab83},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Eccentricity and Inclination Excitation of Stellar Orbits around Merging Black Hole Binaries
AU - Hao Gao
AU - Hanlun Lei
PY - 2026
DA - 2026/10/21
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aeab83
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aeab83
AB - Identifying the formation channels of merging compact-object binaries remains a fundamental challenge in gravitational-wave (GW) astrophysics. Here we formulate a generalized framework incorporating both third-body perturbations and post-Newtonian effects to investigate the resonance-driven excitation of eccentricity and/or inclination for stellar orbits around merging black hole binaries (BHBs). We show that, at the quadrupole level, inclination excitation is driven by adiabatic capture into a quadrupole-order resonance, with subsequent resonance escape governed by the conservation of phase-space area. Furthermore, in the coplanar octupole regime, an apsidal precession resonance triggers robust eccentricity growth, where the capture probability depends on the initial conditions. For spatial octupole configurations, we reveal a distinct two-stage evolutionary pathway: the quadrupole-order resonance first excites the orbital inclination, followed by subsequent eccentricity growth driven by the inverse von Zeipel–Lidov–Kozai (ZLK) resonance. Our results indicate that these resonance-driven dynamics could imprint observable kinematic signatures on surrounding stellar populations, thereby offering a novel indirect probe for merging BHBs.
SN - 0004-637X
SN - 1538-4357
ER -