A quasi-stable stellar system with prolate inner and oblate outer parts

Abstract

The author shows that a stellar system whose morphological structure changes radially from prolate via triaxial to oblate is quasi-stable for 17 crossing times. This configuration is dynamically supported by corresponding radial changes in its velocity anisotropy. The shapes of projected ellipticity profiles of this model take a variety of forms and resemble some observed profiles of elliptical galaxies. Large apparent position angle gradients are common. By way of construction of the model, merging appears to be a promising process for forming elliptical galaxies with ellipticity gradients and isophote twists.