Structural parameters for globular clusters in M31
  In this paper, we present surface brightness profiles for 79 globular
clusters in M31, using images observed with {\it Hubble Space Telescope}, some
of which are from new observations. The structural and dynamical parameters are
derived from fitting the profiles to several different models for the first
time. The results show that in the majority of cases, King models fit the M31
clusters as well as Wilson models, and better than S\'{e}rsic models. However,
there are 11 clusters best fitted by S\'{e}rsic models with the S\'{e}rsic
index $n>2$, meaning that they have cuspy central density profiles. These
clusters may be the well-known core-collapsed candidates. There is a bimodality
in the size distribution of M31 clusters at large radii, which is different
from their Galactic counterparts. In general, the properties of clusters in M31
and the Milky Way fall in the same regions of parameter spaces. The tight
correlations of cluster properties indicate a "fundamental plane" for clusters,
which reflects some universal physical conditions and processes operating at
the epoch of cluster formation.
