Proper Motions in Globular Clusters using Deconvolution of HST Images
  A sub-sampled deconvolution technique for crowded field photometry with the
HST WFPC2 instrument was proposed by Butler (2000) and applied to search for
optical counterparts to pulsars in globular clusters (Golden et al. 2001).
Simulations showed that the method, which takes account of the point-spread
function (PSF) spatial variation, can provide better star detection and
recovers the resolution lost to aberrations and poor sampling. The original
emphasis was on precision photometry in crowded fields. In the present work, we
have extended this technique to determine proper motions of stars in globular
clusters. Actual HST images of the globular clusters, along with realistic
simulations of the globular clusters, were used to benchmark the technique for
astrometric accuracy. The ultimate aim is to use this dynamical data to search
for intermediate-mass black holes in globular cluster cores.
