The Zurich Environmental Study (ZENS) of Galaxies in Groups along the
  Cosmic Web. II. Galaxy Structural Measurements and the Concentration of
  Morphologically Classified Satellites in Diverse Environments
  We present structural measurements for the galaxies in the 0.05<z<0.0585
groups of the Zurich Environmental Study, aimed at establishing how galaxy
properties depend on four environmental parameters: group halo mass M_GROUP,
group-centric distance R/R_200, ranking into central or satellite, and
large-scale structure density delta_LSS. Global galaxy structure is quantified
both parametrically and non-parametrically. We correct all these measurements
for observational biases due to PSF blurring and surface brightness effects as
a function of galaxy size, magnitude, steepness of light profile and
ellipticity. Structural parameters are derived also for bulges, disks and bars.
We use the galaxy bulge-to-total ratios (B/T), together with the calibrated
non-parametric structural estimators, to implement a quantitative morphological
classification that maximizes purity in the resulting morphological samples. We
investigate how the concentration C of satellite galaxies depends on galaxy
mass for each Hubble type, and on M_GROUP, R/R_200 and delta_LSS. At galaxy
masses M>10^10 M_sun, the concentration of disk satellites increases with
increasing stellar mass, separately within each morphological bin of B/T. The
known increase in concentration with stellar mass for disk satellites is thus
due, at least in part, to an increase in galaxy central stellar density at
constant B/T. The correlation between concentration and galaxy stellar mass
becomes progressively steeper for later morphological types. The concentration
of disk satellites shows a barely significant dependence on delta_LSS or
R/R_200. The strongest environmental effect is found with group mass for
M>10^10 M_sun disk-dominated satellites, which are ~10% more concentrated in
high mass groups than in lower mass groups.
