New X-shaped bulge photometric model as a tool for measuring B/PS bulges
  and their X-structures in photometric studies
  Recent orbital studies of 3D bar structure in various numerical and
analytical models show that X-structures that reside in boxy/peanut-shaped
(B/PS) bulges are not delineated by some specific type of orbits, but are
natural parts of them and formed by the same orbits that constitute such
bulges. This implies that to accurately account for B/PS bulges and their
X-structures in photometric studies, one needs the photometric model of B/PS
bulge that includes an X-structure as its natural part. To find such a model,
we considered a self-consistent numerical galaxy model where a typical B/PS
bulge arises. Using spectral characteristics of particle-"stars", we decomposed
the galaxy model onto the bar and non-bar components. We used the extracted 3D
bar component to find an appropriate B/PS bulge photometric model, which can
account for X-structures residing in such bulges. The resulted B/PS bulge
photometric model has a truncated 2D Sersic profile with truncations introduced
above (in the upper half-plane) and below (in the bottom half-plane) the rays
of X-structures. We applied this model to represent B/PS bulges of various
numerical models and some real galaxies. The comparison with previous works
revealed that there are systematic shifts between the X-structure parameters of
the same galaxies measured within the different approaches. We found that the
geometric parameters of X-structures of real and modelled galaxies are
consistent with each other if we measure them using our new model.
