Globular cluster systems in fossil groups: NGC6482, NGC1132 and
  ESO306-017
  We study the globular cluster (GC) systems in three representative fossil
group galaxies: the nearest (NGC6482), the prototype (NGC1132) and the most
massive known to date (ESO306-017). This is the first systematic study of GC
systems in fossil groups. Using data obtained with the Hubble Space Telescope
Advanced Camera for Surveys in the F475W and F850LP filters, we determine the
GC color and magnitude distributions, surface number density profiles, and
specific frequencies. In all three systems, the GC color distribution is
bimodal, the GCs are spatially more extended than the starlight, and the red
population is more concentrated than the blue. The specific frequencies seem to
scale with the optical luminosities of the central galaxy and span a range
similar to that of the normal bright elliptical galaxies in rich environments.
We also analyze the galaxy surface brightness distributions to look for
deviations from the best-fit S\'ersic profiles; we find evidence of recent
dynamical interaction in all three fossil group galaxies. Using X-ray data from
the literature, we find that luminosity and metallicity appear to correlate
with the number of GCs and their mean color, respectively. Interestingly,
although NGC6482 has the lowest mass and luminosity in our sample, its GC
system has the reddest mean color, and the surrounding X-ray gas has the
highest metallicity.
