Spiral Density Wave Theory, Corotation Resonance, and the Velocity Field of NGC 4321

1997 ◽  
Vol 479 (2) ◽  
pp. 723-739 ◽  
Author(s):  
Blaise Canzian ◽  
Ronald J. Allen
Keyword(s):  
Velocity Field ◽  
Density Wave ◽  
Wave Theory ◽  
Spiral Density Wave ◽  
Density Wave Theory

scholarly journals Possible Pattern Speeds of a Density Wave in our Galaxy

1977 ◽  
Vol 45 ◽  
pp. 279-282 ◽  
Author(s):  
Preben J. Grosbøl
Keyword(s):  
Velocity Field ◽  
Spiral Structure ◽  
Density Wave ◽  
Wave Theory ◽  
Young Stars ◽  
Spiral Pattern ◽  
Considerable Effort ◽  
Pattern Speed ◽  
Pattern Speeds ◽  
Density Wave Theory

Since the density wave theory was introduced by Lin and Shu (1964) to explain the spiral structure considerable effort has been made to detect this kind of wave in our galaxy and to determine its parameters. Observations of the distribution and velocity field of gas and young objects show the present shape and location of the spiral pattern in our galaxy but tell little about its angular velocity. It was proposed by Strömgren (1967) to estimate this important parameter by calculating the places of formation of moderately young stars for which accurate space velocities and ages are known. This was done assuming that the majority of stars is formed in spiral arms so that the stellar birthplaces would outline the position of the spiral pattern at different epochs. Later, Yuan (1969) and Wielen (1973) calculated stellar birthplaces in the spiral potential given by Lin et al. (1969). These investigations showed no disagreement with the assumed density wave, however, the number of stars was too small to verify the assumed pattern speed.

scholarly journals Topological defects in crystals: A density-wave theory

1988 ◽  
Vol 10 (1-2) ◽  
pp. 45-51 ◽  
Author(s):  
M Raj Lakshmi ◽  
H R Krishna-Murthy ◽  
T V Ramakrishnan
Keyword(s):  
Density Wave ◽  
Topological Defects ◽  
Wave Theory ◽  
Defects In Crystals ◽  
Density Wave Theory

scholarly journals Fitting the Lin–Shu-type density-wave theory for our own Galaxy★

2013 ◽  
Vol 433 (3) ◽  
pp. 2511-2516 ◽  
Author(s):  
Evgeny Griv ◽  
Chow-Choong Ngeow ◽  
Ing-Guey Jiang
Keyword(s):  
Density Wave ◽  
Wave Theory ◽  
Density Wave Theory

scholarly journals Lifetime of density waves and classification of spirals

1979 ◽  
Vol 84 ◽  
pp. 155-156
Author(s):  
J. V. Feitzinger ◽  
Th. Schmidt-Kaler
Keyword(s):  
Density Wave ◽  
Wave Theory ◽  
Density Waves ◽  
Spiral Arms ◽  
Density Wave Theory

Checking the density-wave theory against observations of our own Galaxy has proven very difficult, as witnessed also at this Symposium. Less ambiguous results, however, are obtained for other galaxies. These results involve a) calculating convincing models for a sample of 25 fairly well observed spirals (Roberts et al. 1975) and b) locating the compression zones on the inner edges of the spiral arms.

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