Chaotic and regular motion in time-dependent barred galaxy models

 

Thanos Manos (Univ. Maribor, Slovenia)

 

I will present a study on the distinction and quantification of chaotic and regular motion in a time-dependent Hamiltonian barred galaxy model. Recently, a strong correlation was found between the strength of the bar and the presence of chaotic motion in this system. Here, I attempt to further explore this connection by studying the interplay between chaotic and regular behavior of star orbits when the parameters of the model evolve in time. This happens for example when one introduces linear time dependence in the mass parameters of the model to mimic the effect of self-consistent interactions of the actual N-body problem. A new way of using the GALI method as a reliable criterion to estimate the relative fraction of chaotic vs. regular orbits in such timedependent potentials is here applied. Finally, I will discuss some preliminary results on the construction and study of a more realistic time-dependent potential which incorporates the time dependencies of all involved parameters (masses, ratios, pattern speed, etc...) of the different components (disk, halo and bar) from real data of N-body simulations.