DENSITY WAVES IN DISK GALAXIES

Author(s):  
C. C. LIN ◽  
F. H. SHU
Keyword(s):  
1967 ◽  
Vol 31 ◽  
pp. 313-317 ◽  
Author(s):  
C. C. Lin ◽  
F. H. Shu

Density waves in the nature of those proposed by B. Lindblad are described by detailed mathematical analysis of collective modes in a disk-like stellar system. The treatment is centered around a hypothesis of quasi-stationary spiral structure. We examine (a) the mechanism for the maintenance of this spiral pattern, and (b) its consequences on the observable features of the galaxy.


1983 ◽  
Vol 100 ◽  
pp. 207-208
Author(s):  
K. O. Thielheim ◽  
H. Wolff

As a generating mechanism of spiral structure, we have recently studied the driving of density waves in the stellar component of disk galaxies by growing barlike perturbations or oval distortions. Numerical experiments (Thielheim and Wolff 1981, 1982) as well as analytical calculations using the first-order epicyclic approximation (Thielheim 1981; Thielheim and Wolff 1982) have been performed, demonstrating that this mechanism is capable of producing two-armed trailing spiral density waves in disks of noninteracting stars. These regular, global spiral structures are similar to those found in N-body experiments on self-consistent stellar disks that show bar instabilities which are weak enough to allow spiral patterns to persist (e.g., Hohl 1978; Berman and Mark 1979; Sellwood 1981). On account of this similarity, we take the view that the spiral structure observed in N-body experiments is primarily not an effect of the self-gravity of the stellar disk but a response phenomenon, caused by the formation of a weak central bar and its subsequent growth due to angular momentum extraction by interaction with the spiral as described by Lynden-Bell and Kalnajs (1972).


1984 ◽  
Vol 75 ◽  
pp. 265-277
Author(s):  
J.B. Holbelg ◽  
W.T. Forrester

ABSTRACTDuring the Voyager 1 and 2 Saturn encounters the ultraviolet spectrometers observed three separate stellar occultations by Saturn's rings. Together these three observations, which sampled the optical depth of the rings at resolutions from 3 to 6 km. can be used to establish a highly accurate distance scale allowing the identification of numerous ring features associated with resonances due to exterior satellites. Three separate observations of an eccentric ringlet near the location of the Titan apsidal resonance are discussed along with other ringlet-resonance associations occurring in the C ring. Density waves occurring in the A and B rings are reviewed and a detailed discussion of the analysis of one of these features is presented.


2003 ◽  
Vol 10 ◽  
pp. 95-95
Author(s):  
E. Ardi ◽  
T. Tsuchiya ◽  
A. Burkert

1999 ◽  
Vol 09 (PR10) ◽  
pp. Pr10-161-Pr10-163
Author(s):  
H. Matsukawa ◽  
H. Miyake ◽  
M. Yumoto ◽  
H. Fukuyama

1999 ◽  
Vol 09 (PR10) ◽  
pp. Pr10-129-Pr10-132 ◽  
Author(s):  
J. P. McCarten ◽  
T. C. Jones ◽  
X. Wu ◽  
J. H. Miller ◽  
I. Pirtle ◽  
...  

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