  Using integral field spectroscopy from MaNGA, we study the resolved
microstructures in a shocked region in Criss Cross Nebula (CCN), with an
unprecedentedly high resolution of $\lesssim$1000 AU. We measure surface
brightness maps for 34 emission lines, which can be broadly divided into three
categories: (1) the [OIII] $\lambda$5007-like group including seven
high-ionization lines and two [OII] auroral lines which uniformly present a
remarkable lane structure, (2) the H$\alpha$ $\lambda$6563-like group including
23 low-ionization or recombination lines which present a clump-like structure,
and (3) [OII] $\lambda$3726 and [OII] $\lambda$3729 showing high densities at
both the [OIII] $\lambda$5007 lane and the H$\alpha$ clump. We use these
measurements to constrain resolved shock models implemented in MAPPINGS V. We
find our data can be reasonably well-fitted by a model which includes a
plane-parallel shock with a velocity of $133\pm5$ km/s, plus an isotropic
two-dimensional Gaussian component which is likely another clump of gas ionized
by photons from the shocked region, and a constant background. We compare the
electron density and temperature profiles as predicted by our model with those
calculated using observed emission line ratios. We find different line ratios
to provide inconsistent temperature maps, and the discrepancies can be
attributed to observational effects caused by limited spatial resolution and
projection of the shock geometry, as well as contamination of the additional
Gaussian component. Implications on shock properties and perspectives on future
IFS-based studies of CCN are discussed.
