No CrossRef data available.
Published online by Cambridge University Press: 25 May 2016
The study of stability of the stellar disks of flat galaxies is the first step towards an understanding of the phenomena of spiral structure. To explain the spiral pattern, Lin and Shu (1964) further developed the Lindblad's idea of density waves by considering the spiral structure as the collective effect in a self-gravitating system. As an extension to the original Lin-Shu theory, unstable spiral modes have been obtained from an asymptotic analysis (e.g., Bertin [1980]). In such “modal theory”, the Jeans-type instability (even weak) is important to the maintenance of spiral structure.