文章基本信息

标题：Unstable spiral modes in disk-shaped galaxies
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作者：Y. Y. Lau ; C. C. Lin ; James W.-K. Mark 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1976
卷号：73
期号：5
页码：1379-1381
DOI：10.1073/pnas.73.5.1379
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：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 relationship is given as a definite integral, which allows the immediate determination of the pattern frequency and the amplification rate, once the basic galactic model is known.
关键词：density waves ; galactic dynamics ; spiral arms