  Analysis of the globular cluster (GC) system of the giant elliptical (E3)
galaxy NGC 4365, from eight Hubble Space Telescope/Advanced Camera for Surveys
(ACS) pointings and a wide-field Subaru/SuprimeCam (S-Cam) image, is presented.
We determine the lower limit on the number of GCs to be 6450+-110 and show that
the GC system extends beyond 134 kpc (9.5 galaxy effective radii). We revisit
the question of whether NGC 4365 has a bimodal or trimodal GC colour
distribution and find support for three distinct GC colour subpopulations (i.e.
blue, green and red). Sersic profile fits to the radial surface density of each
subpopulation reveal that the blue GCs are more extended than either red or
green GCs. We find significant differences in the median half light radii for
GCs in the blue, green and red subpopulations as well as in the subpopulation
ellipticities. A KS test on the mass functions show >98 per cent probability
that all three subpopulations are distinct from one another. We also find
radial gradients of GC size and colour (metallicity) and a blue tilt. The
properties, including surface density profile, position angle, ellipticity and
radial colour gradient, of the red GC subpopulation are very similar to the
properties of NGC 4365's starlight. This result supports the hypothesis that
red GCs are formed along with the bulk of the diffuse starlight in the galaxy.
NGC 4365 has a kinematically distinct core and a significant misalignment
between the photometric and kinematic major axes. We discuss the possibility
that these kinematic features are related to the presence of the distinct third
GC subpopulation. We briefly discuss implications for the formation of NGC
4365. (Condensed from original.)
