Compact Groups analysis using weak gravitational lensing II: CFHT Stripe
  82 data
  In this work we present a lensing study of Compact Groups (CGs) using data
obtained from the high quality Canada-France-Hawaii Telescope Stripe 82 Survey.
Using stacking techniques we obtain the average density contrast profile. We
analyse the lensing signal dependence on the groups surface brightness and
morphological content, for CGs in the redshift range $z = 0.2 - 0.4$. We obtain
a larger lensing signal for CGs with higher surface brightness, probably due to
their lower contamination by interlopers. Also, we find a strong dependence of
the lensing signal on the group concentration parameter, with the most
concentrated quintile showing a significant lensing signal, consistent with an
isothermal sphere with $\sigma_V =336 \pm 28$ km/s and a NFW profile with
$R_{200}=0.60\pm0.05$ $h_{70}^{-1}$Mpc. We also compare lensing results with
dynamical estimates finding a good agreement with lensing determinations for
CGs with higher surface brightness and higher concentration indexes. On the
other hand, CGs that are more contaminated by interlopers show larger dynamical
dispersions, since interlopers bias dynamical estimates to larger values,
although the lensing signal is weakened.
