Formation of shell galaxies. II - Nonspherical potentials

Abstract

The formation of shells through interactions of low-mass companions with nonspherical galaxies is investigated using the restricted three-body method. We find that sharp-edged features remain a common outcome of such encounters, regardless of the detailed structure of the more massive galaxy. The morphology and alignment of the resulting shell system are sensitive to the form of the potential of the primary galaxy; however, they depend also on the orbital parameters of the collision and on the nature of the companion. The latter two considerations imply that it will be difficult to infer the intrinsic shapes of luminous ellipticals from observations of shells. 22 refs.