Bars in field and cluster galaxies at intermediate redshifts
  We present the first study of large-scale bars in clusters at intermediate
redshifts (z=0.4-0.8). We compare the properties of the bars and their host
galaxies in the clusters with those of a field sample in the same redshift
range. We use a sample of 945 moderately inclined disk galaxies drawn from the
EDisCS project. The morphological classification of the galaxies and the
detection of bars are based on deep HST/ACS F814W images. The total optical bar
fraction in the redshift range z=0.4-0.8, averaged over the entire sample, is
25%. This is lower than found locally, but in good agreement with studies of
bars in field environments at intermediate redshifts. For the cluster and field
subsamples, we measure bar fractions of 24% and 29%, respectively. In agreement
with local studies, we find that disk-dominated galaxies have a higher bar
fraction than bulge-dominated galaxies. We also find, based on a small
subsample, that bars in clusters are on average longer than in the field and
preferentially found close to the cluster center, where the bar fraction is
somewhat higher than at larger distances.
