Outer density profiles of 19 Galactic globular clusters from deep and
  wide-field imaging
  Using deep photometric data from WFC@INT and WFI@ESO2.2m we measure the outer
number density profiles of 19 stellar clusters located in the inner region of
the Milky Way halo (within a Galactocentric distance range of 10-30 kpc) in
order to assess the impact of internal and external dynamical processes on the
spatial distribution of stars. Adopting power-law fitting templates, with index
$-\gamma$ in the outer region, we find that the clusters in our sample can be
divided in two groups: a group of massive clusters ($ \ge 10^5 $ M_sun) that
has relatively flat profiles with $2.5 < \gamma < 4$ and a group of low-mass
clusters ($ \le 10^5 $ M_sun), with steep profiles ($\gamma > 4$) and clear
signatures of interaction with the Galactic tidal field. We refer to these two
groups as 'tidally unaffected' and 'tidally affected', respectively. Our
results also show a clear trend between the slope of the outer parts and the
half-mass density of these systems, which suggests that the outer density
profiles may retain key information on the dominant processes driving the
dynamical evolution of Globular Clusters.
