Summary
We continue the theoretical investigation of geostrophically balanced motions of a star gas in a rotating galaxy. The method of small perturbations is employed to derive a quasi geostrophic vorticity equation suitable for solving initial value problems for ‘slow’ galactic eddying motions. The results derived for this simple theoretical model are then generalized to obtain approximate geostrophic forecast equations suitable for study of nonlinear galactic motions over a whole disk galaxy. A simple discussion of the stability of our approximate vorticity equation is presented. It is expected that in the absence of rapid gravitational instabilities, actual eddy motions observed in spiral galaxies will be at least approximately of the type of motion discussed in this paper. The Rossby adjustment problem is investigated in this context.
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References
S. Chandrasekhar,The Principles of Stellar Dynamics, University of Chicago Press (1942).
S. Chandrasekhar,Hydrodynamic and Hydramagnetic Stability, Oxford Press (1961).
J. G. Charney,On the scale of atmospheric motions, Geophys. Publ.17 (1948), 2.
R. E. Dickinson,Analysis of large scale disturbances in spiral galaxies, Geofis. pura e appl.56 (1963), 174.
R. E. Dickinson,Hydrodynamic conservation integrals for galaxies, Pure and appl. Geophys.59 (1964), 142.
C. C. Lin,The Theory of Hydrodynamic Stability, Cambridge University Press (1955).
C. C. Lin,On the spiral structure of disk galaxies, (1962) (unpublished manuscript).
B. Lindblad,Galactic dynamics, Hdb. PhysikLIII (1959), 21.
P. O. Lindblad,Gravitational resonance effects and the formation of spiral structure, Soviet Astronomy, A. J.5, 3 (1961), 376.
R. A. Lyttleton,The Stability of Rotating Liquid Masses, Cambridge University Press (1953).
J. H. Oort,Radio frequency studies of galactic structure, Hdb. PhysikLIII (1959), 100.
J. H. Oort,Spiral structure, inThe Distribution and Motion of Interstellar Matter in Galaxies (L. Woltjer, W. A. Benjamin, N. Y. 1962), 234.
N. G. Phillips,Geostrophic motion, Rev. Geophys.1, 2 (1963), 123.
C. G. Rossby,On the mutual adjustment of pressure and velocity distribution in certain simple current systems, 2, J. Marine Res.1, 3 (1938), 239.
V. P. Starr,Hydrodynamical red-shift phenomena in geophysics, Geofis. pura e appl.48 (1961), 109.
V. P. Starr andR. E. Newell,Pilot calculations of the flux of angular momentum in a spiral galaxy, Pub. Ast. Soc. Pac.75, 444 (1963), 239.
V. P. Starr andJ. P. Peixoto,Certain basic atmospheric processes and their counterparts in celestial mechanics. Geofis. pura e appl.51 (1962), 171.
P. D. Thompson,Numerical Weather Analysis and Prediction (Macmillan, New York 1961).
A. Toomre,On gravitational instability in spiral galaxies IDisk of Stars, Ap. J.140 (1964).
M. Wallace andJ. Copeland,Velocity field in a model of a spiral galaxy, P.A.S.P. (1964).
F. Ward,General circulation of the solar atmosphere from observational evidence, Pure and appl. Geophys.58 (1964), 157.
F. Webster,The effect of meanders on the kinetic energy balance of the Gulf Stream, Tellus13 (1961), 392.
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Dickinson, R.E. Quasi-geostrophic motions in a galactic flow. PAGEOPH 59, 155–171 (1964). https://doi.org/10.1007/BF00880516
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DOI: https://doi.org/10.1007/BF00880516