The SLUGGS survey: combining stars, globular clusters and planetary
  nebulae to understand the assembly history of early-type galaxies from their
  large radii kinematics
  We investigate the kinematic properties of nine nearby early-type galaxies
with evidence of a disk-like component. Three of these galaxies are located in
the field, five in the group and only one in the cluster environment. By
combining the kinematics of the stars with those of the globular clusters (GCs)
and planetary nebulae (PNe), we probe the outer regions of our galaxies out to
$\sim$4-6 Re. Six galaxies have PNe and red GCs that show good kinematic
alignment with the stars, whose rotation occurs along the photometric
major-axis of the galaxies, suggesting that both the PNe and red GCs are good
tracers of the underlying stellar population beyond that traced by the stars.
Additionally, the blue GCs also show rotation that is overall consistent with
that of the red GCs in these six galaxies. The remaining three galaxies show
kinematic twists and misalignment of the PNe and GCs with respect to the
underlying stars, suggesting recent galaxy interactions. From the comparison
with simulations, we propose that all six aligned galaxies that show similar
dispersion-dominated kinematics at large radii (>2-3 Re) had similar late
($z<1$) assembly histories characterised by mini mergers (mass-ratio <1:10).
The different Vrot/$\sigma$ profiles are then the result of an early ($z>1$)
minor merger (1:10< mass-ratio <1:4) for the four galaxies with peaked and
decreasing Vrot/$\sigma$ profiles and of a late minor merger for the two
galaxies with flat Vrot/$\sigma$ profiles. The three mis-aligned galaxies
likely formed through multiple late minor mergers that enhanced their velocity
dispersion at all radii, or a late major merger that spun-up both the GC
sub-populations at large radii. Therefore, lenticular galaxies can have complex
merger histories that shape their characteristic kinematic profile shapes.
