Resonance excitation: A possible interpretation of the 3-KPC arm

  • Chi Yuan
  • Ye Cheng
III. Spiral Structure
Part of the Lecture Notes in Physics book series (LNP, volume 306)


A minor oval distortion or an uneven distribution of mass in the central region of the Galaxy may excite an outgoing spiral wave that closely resembles the observed 3-kpc arm. The wave is generated by a resonance excitation mechanism at the outer Lindblad resonance corresponding to the pattern frequency of the oval distortion or of the uneven distribution of the mass. An expansion velocity of 53 km/sec associated with the wave crest requires a perturbational field of 5% of the local mean gravitational field. The calculations are based on a non-linear analysis of gas motions in a disk system with the inclusion of self-gravitation and viscosity.


Galactic Center Expansion Velocity Spiral Density Wave Lindblad Resonance Angular Momentum Flux 


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Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • Chi Yuan
    • 1
  • Ye Cheng
    • 1
  1. 1.Department of PhysicsThe City College of New YorkNew York

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