The outer halo globular cluster system of M31 - I. The final PAndAS
  catalogue
  We report the discovery of 59 globular clusters (GCs) and two candidate GCs
in a search of the halo of M31, primarily via visual inspection of CHFT/MegaCam
imagery from the Pan-Andromeda Archaeological Survey (PAndAS). The superior
quality of these data also allow us to check the classification of remote
objects in the Revised Bologna Catalogue (RBC), plus a subset of GC candidates
drawn from SDSS imaging. We identify three additional new GCs from the RBC, and
confirm the GC nature of 11 SDSS objects (8 of which appear independently in
our remote halo catalogue); the remaining 188 candidates across both lists are
either foreground stars or background galaxies. Our new catalogue represents
the first uniform census of GCs across the M31 halo - we find clusters to the
limit of the PAndAS survey area at projected radii of up to R_proj ~ 150 kpc.
Tests using artificial clusters reveal that detection incompleteness cuts in at
luminosities below M_V = -6.0; our 50% completeness limit is M_V ~ -4.1. We
construct a uniform set of PAndAS photometric measurements for all known GCs
outside R_proj = 25$ kpc, and any new GCs within this radius. With these data
we update results from Huxor et al. (2011), investigating the luminosity
function (LF), colours and effective radii of M31 GCs with a particular focus
on the remote halo. We find that the GCLF is clearly bimodal in the outer halo
(R_proj > 30 kpc), with the secondary peak at M_V ~ -5.5. We argue that the GCs
in this peak have most likely been accreted along with their host dwarf
galaxies. Notwithstanding, we also find, as in previous surveys, a substantial
number of GCs with above-average luminosity in the outer M31 halo - a
population with no clear counterpart in the Milky Way.
