The SLUGGS Survey: Kinematics for over 2500 Globular Clusters in Twelve
  Early-type Galaxies
  We present a spectro-photometric survey of 2522 extragalactic globular
clusters (GCs) around twelve early-type galaxies, nine of which have not been
published previously. Combining space-based and multi-colour wide field
ground-based imaging, with spectra from the Keck DEIMOS instrument, we obtain
an average of 160 GC radial velocities per galaxy, with a high velocity
precision of 15 km/s per GC. After studying the photometric properties of the
GC systems, such as their spatial and colour distributions, we focus on the
kinematics of metal-poor (blue) and metal-rich (red) GC subpopulations to an
average distance of ~8 effective radii from the galaxy centre. Our results show
that for some systems the bimodality in GC colour is also present in GC
kinematics. The kinematics of the red GC subpopulations are strongly coupled
with the host galaxy stellar kinematics. The blue GC subpopulations are more
dominated by random motions, especially in the outer regions, and decoupled
from the red GCs. Peculiar GC kinematic profiles are seen in some galaxies: the
blue GCs in NGC 821 rotate along the galaxy minor axis, whereas the GC system
of the lenticular galaxy NGC 7457 appears to be strongly rotation supported in
the outer region. We supplement our galaxy sample with data from the literature
and carry out a number of tests to study the kinematic differences between the
two GC subpopulations. We confirm that the GC kinematics are coupled with the
host galaxy properties and find that the velocity kurtosis and the slope of
their velocity dispersion profiles is different between the two GC
subpopulations in more massive galaxies.
