Unstable spiral modes in disk-shaped galaxies.

  title={Unstable spiral modes in disk-shaped galaxies.},
  author={Yue Ying Lau and C. C. Lin and James W.-K. Mark},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  volume={73 5},
  • Y. Lau, C. Lin, J. Mark
  • Published 1 May 1976
  • Chemistry, Medicine
  • Proceedings of the National Academy of Sciences of the United States of America
The mechanisms for the maintenance and the excitation of trailing spiral modes of density waves in diskshaped galaxies, as proposed by Lin in 1969 and by Mark recently, are substantiated by an analysis of the gas-dynamical model of the galaxy. The self-excitation of the unstable mode in caused by waves propagating outwards from the corotation circle, which carry away angular momentum of a sign opposite to that contained in the wave system inside that circle. Specifically, a simple dispersion… 
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