2003ApJ...586..780C

We present detailed numerical N-body simulations of the dynamical interaction of disk galaxies embedded in a spherical halo of dark matter and an orbiting satellite, in order to study the relationship between the kinematics and the stellar distribution of the disk. The satellite is held on a fixed, coplanar, eccentric (e=1/3), or nearly circular (e=0.02) orbit. It is shown that the density wave mode m=1 has an average phase angle shift of about 30° from the positive tangential velocity wave mode m=1 but presents greater values just after the pericentric satellite passage. It is also shown that the density m=2 coincides (within 10° on average) with the positive tangential velocity wave mode m=2. The pattern speeds obtained from the density and the three velocity component distributions are the same. The asymmetry parameter (A) derived from the stellar distribution agrees with the asymmetry parameter derived from the velocity field. The A(180°) mode is dominant in comparison to A(90°) when we consider the center of mass of the disk. However, this behavior is reversed when we calculate the asymmetry using the center of density of the disk or center of maximum luminosity.