  In an effort to probe the globular cluster (GC) system of an isolated
elliptical galaxy, a comprehensive analysis of the NGC 821 GC system was
performed. New imaging from the WIYN Mini-Mosaic imager, supplemented with
Hubbl e Space Telescope (HST) WFPC2 images reveals a GC system similar to those
found in counterpart ellipticals located in high-density environments. To put
these results into the context of galaxy formation, a robustly-determined
census of GC systems is presented and analysed for galaxies spanning a wide
range of masses (> M_star), morphologies and environments.
  Results from this meta-study: (1) confirm previous findings that the number
of GCs normalized by host galaxy stellar mass increases with host stellar mass.
Spiral galaxies in the sample show smaller relative GC numbers than those of
massive ellipticals, suggesting the GC systems of massive ellipticals were not
formed from major spiral-spiral mergers; (2) indicate that GC system numbers
per unit galaxy baryon mass increases with host baryon mass and that GC
formation efficiency may not be universal as previously thought; (3) suggest
previously reported trends with environment may be incorrect due to sample bias
or the use of galaxy stellar masses to normalize GC numbers. Thus claims for
environmentally dependent GC formation efficiencies should be revisited; (4) in
combination with weak-lensing halo mass estimates, suggest that GCs formed in
direct proportion to the halo mass; (5) are consistent with theoretical
predictions whereby the local epoch of re-ionization did not vary significantly
with environment or host galaxy type.
