Triaxial Elliptical Galaxies
So, are ellipticals simple to understand dynamically?
Not so clear.  We’re seeing a 2D picture of a 3D object.
In general, elliptical galaxies rotate too slowly for this
to account for the flattening observed.  In other words,
their ratios of rotational to random kinetic energy is
too low.
If ellipticity e were due to rotation (e.g., a pure oblate
rotator with an isotropic velocity distribution) then
(Vrot/σ)iso ~ (e/(1-e))1/2.  Is it?