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Distribution of Kolmogorov-Sinaï Entropy in Self-Consistent Models of Barred Galaxies

Published online by Cambridge University Press:  12 April 2016

H. Wozniak  and
D. Pfenniger
H. Wozniak
Affiliation:
IGRAP/Observatoire de Marseille, F-13248 Marseille cedex 4, FranceE-mail:wozniak@observatoire.cnrs-mrs.fr
D. Pfenniger
Affiliation:
Observatoire de Genève, CH-1290 Sauverny, SwitzerlandE-mail:Daniel.Pfenniger@obs.unige.ch

Abstract

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The properties of chaos in 2D self-consistent models of barred galaxies are investigated using Kolmogorov-Sinai entropy hKS. These models are constructed with Schwarzschild’s method which combines orbits as elementary building blocks.

Most models are dominated by chaos near the 2/3 of the length of the bar and close to corotation. These locations correspond to regions where star-forming HII regions are observed because gas clouds could shock, shrink and fragment such that star formation could be ignited.

The model the most similar to N-body models shows a peak of hKS between the corners of the rectangular-like x1 orbits and the maximum extension points of the Lagrangian orbits. This emphasizes the role of Lagrangian orbits in the morphology of bars. Most models essentially contain ‘semi-chaotic’ orbits confined inside the corotation.

Type
Stellar Systems
Information
International Astronomical Union Colloquium , Volume 172: Impact of Modern Dynamics in Astronomy , 1999 , pp. 149 - 158
Copyright
Copyright © Kluwer 1999

References

Chvátal, V.: 1983, Linear Programming, Freeman, New York Google Scholar
Ferrers, N.M.: 1877, Quart. J. Pure Appl. Math. 14, 1 Google Scholar
Freeman, K.C.: 1966, Mon. Not. R. Astr. Soc. 134, 1 Google Scholar
Kaufmann, D.E.: 1993, Ph D. Thesis, Univ. of Florida Google Scholar
Kaufmann, D.E., Contopoulos, G.: 1996, A&A 309, 381 Google Scholar
Lawson, C.L., Hanson, R.J.: 1974, Solving Least Squares Problems, Prentice-Hall, Englewood Cliffs, New Jersey; 1995, Classic in Applied Mathematics 15, SIAM, Philadelphia (updated NNLS routines are available at http://www.netlib.org)Google Scholar
Pesin, Y.B.: 1977, Russ. Math. Surveys 32, 55 Google Scholar
Pfenniger, D.: 1984a, A&A 134, 373 Google Scholar
Pfenniger, D.: 1984b, A&A 141, 171 Google Scholar
Pfenniger, D.: 1985, Ph D Thesis, University of Geneva Google Scholar
Pfenniger, D., Friedli, D.: 1991, A&A 252, 75 Google Scholar
Schwarzschild, M.: 1979, Apj 232, 236 Google Scholar
Sparke, L., Sellwood, J.A., 1987, MNRAS 225, 653 Google Scholar
Udry, S., Pfenniger, D.: 1988, A&A 198, 135 Google Scholar
Wozniak, H.: 1991 a, Ph.D. Thesis, University of Paris 7 Google Scholar
Wozniak, H.: 1994, in Ergodic Concepts in Stellar Dynamics, Gurzadyan, V.G. & Pfenniger, D. (eds.), Lecture Notes in Physics 430, Springer-Verlag, Heidelberg, p. 264 Google Scholar
Wozniak, H., Pfenniger, D., 1996, in: Barred Galaxies, Buta, R., Elmegreen, B.G., Crocker, D.A. (eds.), Proc. IAU Coll 157, ASP Conferences Series, p. 445 Google Scholar
Wozniak, H., Pfenniger, D.: 1997, A&A 317, 14 Google Scholar
Zhao, H.: 1996, MNRAS, 283, 149 Google Scholar