Theory of spiral structure.The question whether the galactic spiral arms are material objects or wave patterns is discussed. A semiempirical approach is adopted in presenting the concept of density waves. The theory of density waves is considered, giving attention to a survey of theoretical developments by analytical methods, the implication of a spiral pattern of density waves, spirals with moderately small pitch angle, and the origin and permanence of galactic spirals. The theoretical aspects discussed are tested against more detailed observations in the Milky Way system. It is pointed out that the density wave concept introduced by Lindblad, including the material concentration of both gas and stars, is the essential basis for the spiral structure of disk-shaped galaxies.
Document ID
19720029439
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Lin, C. C. (MIT Cambridge, Mass., United States)
Date Acquired
August 6, 2013
Publication Date
January 1, 1971
Subject Category
Space Sciences
Meeting Information
Meeting: Highlights of astronomy. Volume 2 - International Astronomical Union, General Assembly