Nearly coeval intermediate-age Milky Way star clusters at very different
  dynamics evolutionary stages
  We report astrophysical properties of 12 Milky Way open clusters located
beyond the circle around the Sun where the number of catalogued open clusters
is thought to be statistically complete. By using deep optical photometry, we
estimated their ages and metallicities on the basis of a maximum likelihood
approach, using cluster members identified from Gaia DR2 data and likelihood
procedures. The studied clusters turned out to be of intermediate-age (0.8 -
4.0 Gyr), with metallicities spanning the range [Fe/H] ~ -0.5 - +0.1 dex, and
distributed within the general observed trend of the Milky Way disc radial and
perpendicular metallicity gradients. As far as we are aware, these are the
first metal abundance estimates derived for these clusters so far. From the
constructed stellar density radial profiles and cluster mass functions we
obtained a variety of structural and internal dynamics evolution parameters.
They show that while the innermost cluster regions would seem to be mainly
shaped according to the respective internal dynamics evolutionary stages, the
outermost ones would seem to be slightly more sensitive to the Milky Way tidal
field. The nearly coeval studied clusters are experiencing different levels of
two-body relaxation following star evaporation; those at more advanced stages
being more compact objects. Likewise, we found that the more important the
Milky way tides, the larger the Jacobi volume occupied by the clusters,
irrespective of their actual sizes and internal dynamics evolutionary stages.
