The Globular Cluster System of the Virgo Giant Elliptical Galaxy NGC
  4636: II. Kinematics of the Globular Cluster System
  We present a kinematic analysis of the globular cluster(GC) system in the
giant elliptical galaxy (gE) NGC 4636 in the Virgo cluster. Using the
photometric and spectroscopic database of 238 GCs, we have investigated the
kinematics of the GC system. The NGC 4636 GC system shows weak overall
rotation, which is dominated by the red GCs. However, both the blue GCs and red
GCs show some rotation in the inner region at R<4.3'. The velocity dispersion
for all the GCs is derived to be sigma_p = 225{+12-9} km/s. The velocity
dispersion for the blue GCs (sig=251 km/s) is slightly larger than that for the
red GCs (sig=205 km/s). The velocity dispersions for the blue GCs about the
mean velocity and about the best fit rotation curve have a significant
variation depending on the galactocentric radius. Comparison of observed
stellar and GC velocity dispersion profiles with the velocity dispersion
profiles calculated from the stellar mass profile shows that the mass-to-light
ratio should increase as the galactocentric distance increases, indicating the
existence of an extended dark matter halo. From the comparison of the observed
GC velocity dispersion profiles and the velocity dispersion profiles calculated
for the X-ray mass profiles in the literature, we find that the orbit of the GC
system is tangential, and that the orbit of the red GCs is slightly more
tangential than that of the blue GCs. We compare the GC kinematics of NGC 4636
with those of other six gEs, finding that the kinematic properties of the GCs
are diverse among gEs. We find several correlations between the kinematics of
the GCs and the global parameters of their host galaxies. We discuss the
implication of the results for the formation models of the GC system in gEs,
and suggest a mixture scenario for the origin of the GCs in gEs.
