Extended Star Clusters in NGC 1023 from HST/ACS Mosaic Imaging
  Faint fuzzies are a relatively new class of star cluster, first found in the
nearby S0 galaxy NGC 1023 by Larsen & Brodie using WFPC2 images from the Hubble
Space Telescope (HST). Here we investigate the star cluster system of NGC 1023
using an eight pointing mosaic of ACS images from HST. We identify blue and red
normal globular clusters (two of which are particularly luminous and dense) and
two ultra compact dwarf objects (with effective radius ~10 pc). With our more
complete spatial coverage, we also find 81 red and 27 blue faint fuzzies (FFs).
We confirm the association of the red FFs with the disk of NGC 1023, consistent
with them being long-lived open clusters. Half of the blue FFs appear to be
associated with the dwarf satellite galaxy NGC 1023A (which was largely absent
from the original HST/WFPC2 coverage), while the remainder are spatially
coincident with the densest HI gas that surrounds NGC 1023. The blue FFs have
colours that are consistent with young (few 100 Myr old) star clusters that
formed during the most recent interaction between NGC 1023 and its satellite
NGC 1023A.
