Structural Parameters of Seven SMC Intermediate-Age and Old Star
  Clusters
  We present structural parameters for the seven intermediate-age and old star
clusters NGC121, Lindsay 1, Kron 3, NGC339, NGC416, Lindsay 38, and NGC419 in
the Small Magellanic Cloud. We fit King profiles and Elson, Fall, and Freeman
profiles to both surface-brightness and star count data taken with the Advanced
Camera for Surveys aboard the Hubble Space Telescope. Clusters older than 1 Gyr
show a spread in cluster core radii that increases with age, while the youngest
clusters have relatively compact cores. No evidence for post core collapse
clusters was found. We find no correlation between core radius and distance
from the SMC center, although consistent with other studies of dwarf galaxies,
some relatively old and massive clusters have low densities. The oldest SMC
star cluster, the only globular NGC121, is the most elliptical object of the
studied clusters. No correlation is seen between ellipticity and distance from
the SMC center. The structures of these massive intermediate-age (1-8 Gyr) SMC
star clusters thus appear to primarily result from internal evolutionary
processes.
