Dynamical Properties of Tidally Induced Galactic Bars

We simulated a series of fully three-dimensional N-body models of tidal encounters between a disk galaxy and a perturbing galaxy to investigate the dynamical properties of tidally induced galactic bars, especially in connection with the resonance structure, which we have little knowledge about. We also calculated another set of N-body models on isolated galaxies with bar-unstable disks to make a comparison between galactic bars of different origins. To reveal the resonances in a highly nonaxisymmetric potential for which the ordinary method of deriving resonances using the Ω ± κ/2 curves gives unreliable results, we employed the analysis based on the families of periodic orbits in a barred potential.