2002ApJ...580..705K

A combined particle-mesh N-body/gridded hydrodynamics/stellar evolution code is employed to model the response of a galaxy disk to an impulsive perturbation. The resulting galaxy is examined for asymmetry in morphology and dynamics to answer the question of whether free ``sloshing'' librations in the plane of the disk can explain the relatively large proportion of asymmetric field spirals. The simulation produced a perturbed disk containing streamers of gas and stars, gas shocks, and m=1 and m=2 spiral structure. Strong kinematic peculiarities were generated as well. However, although the resulting disk reproduced many of the kinematic features observed in H I synthesis maps, the effects are relatively short-lived, lasting only on the order of a dynamical timescale. The similarities between the model and the tidally deformed galaxy NGC 5474, however, do leave open the possibility of forced sloshing modes playing a role in galaxies undergoing tidal interactions.