The SLUGGS Survey: outer triaxiality of the Fast Rotator elliptical NGC
  4473
  Systematic surveys of nearby early type galaxies (ETGs) using integral field
unit spectrograph (IFU) data have revealed that galaxies can hide interesting
structures only visible through kinematic studies. As part of their pioneering
work, the ATLAS3D team have shown that most morphologically elliptical galaxies
are centrally kinematically disk-like. Hence, while global morphology suggests
that ellipticals are ellipsoidal/triaxial in shape, their central kinematics
may be consistent with (inclined) oblate systems.
  Here we study the Fast Rotator elliptical galaxy: NGC 4473. Using slitlets,
we obtain galaxy light kinematics out to unprecedentedly large galactocentric
radii (2.5 effective radii). While we confirm the IFU results in the central
regions, we find that at large galactocentric radii NGC 4473 exhibits a
kinematic transition. In the outskirts, we observe clear minor and major axis
rotation, a tell-tale sign of triaxiality, which agrees well with the galaxy's
Hubble type.
  This outer "kinematically distinct halo" (KDH) may be expected from
simulations of galaxy formation, and in this system contains around one-third
of the stellar light. While this galaxy may be a special case, it suggests
further investigation of the outskirts of galaxies is needed to confirm the new
paradigm of galaxy classification.
