Bar and spiral orbital resonances
Research context
research method · conditional · As of 2026-10-10
Rotating nonaxisymmetric potentials exchange angular momentum at corotation and Lindblad resonances.
Key knowledge
Rotating nonaxisymmetric potentials exchange angular momentum at corotation and Lindblad resonances. Linear epicyclic response is singular near resonances and must be replaced by trapped-orbit or nonlinear dynamics there; resonances can move as a bar slows.
Values and equations
m(Ω-Ω_p)=±κ (Lindblad); Ω=Ω_p (corotation)
- m
- Azimuthal perturbation order 1
- Ω
- Circular angular frequency s^-1
- Ω_p
- Pattern angular frequency s^-1
- κ
- Radial epicyclic frequency s^-1
Conditions and scope
- The displayed frequencies describe near-circular planar orbits in an axisymmetric background with a weak m-fold perturbation.
- Gas shocks/dissipation and collisionless orbit trapping have different transport mechanisms.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Internal evolution: bars and resonances: Sections 20.2–20.3: rotating-frame orbits, Lindblad/corotation resonances and transport (selected source body inspected).
2026-10-10 · Bounded source check of the recorded statement and conditions. This does not certify a unique physical model, reproduce the cited study or replace independent branch review.
Entry details
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- research-earth-bar-resonances
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference