  It is well known that Globular cluster systems are different among galaxies.
Here we test to which degree these differences remain on the scale of galaxy
clusters by comparing the globular clusters (GCs) in optical surveys of the
Virgo galaxy cluster (ACSVCS) and the Fornax galaxy cluster (ACSFCS) in
Kolmogorov-Smirnoff Tests. Both surveys were obtained with the Advanced Camera
for Surveys (ACS) on board the Hubble Space Telescope, and contain thousands of
GCs in dozens of galaxies each. Also well over 100 point sources in the Chandra
X-ray Observatory source catalogue were attributed to the GCs in both optical
catalogues, and interpreted as low-mass X-ray binaries (LMXBs). Thus, the
optical and X-ray data are as uniform as possible. Our main findings are as
follows: (1) The spread in luminosities and half-light radii is larger in the
ACSVCS than in the ACSFCS. (2) The ratio between the half-light radii for the
F475W-passband and the F850LP-passband is on average smaller in the ACSVCS. (3)
The distribution of the LMXBs with the luminosity of the GCs is different
between both surveys. These findings are significant. The first finding could
be a consequence of a wider spread in the distances of the GCs in the ACSVCS,
but the others must have internal reasons in the GCs. Thus, the GC systems are
also different on a galaxy cluster scale.
