Distribution of Kolmogorov-Sinai entropy in self-consistent models of barred galaxies

The properties of chaos in 2D self-consistent models of barred galaxies are investigated using Kolmogorov-Sinai entropy h(KS). These models are constr ucted with Schwarzschild's method which combines orbits as elementary build ing blocks. Most models are dominated by chaos near the 2/3 of the length of the bar an d close to corotation. These locations correspond to regions where star for ming HII regions are observed because gas clouds could shock, shrink and fr agment such that star formation could be ignited. The model the most similar to N-body models shows a peak of h(KS) between t he corners of the rectangular-like x(1) orbits and the maximum extension po ints of the Lagrangian orbits. This emphasizes the role of Lagrangian orbit s in the morphology of bars. Most models essentially contain 'semi-chaotic' orbits confined inside the corotation.