  Recent deep Chandra observations of nearby Compton thick (CT) AGN have
produced surprising results, uncovering extended emission not only in the soft
X-rays but in the hard emission (>3 keV), challenging the long-held belief that
the characteristic hard X-ray continuum and fluorescent Fe Ka lines are
associated with the torus in the standard picture of AGN. In this work, we
present the analysis of our deep (~261 ks) X-ray Chandra ACIS-S observations of
NGC 5728, a nearby (z=0.00932) CT AGN. We find that the diffuse emission is
more extended at lower energies, in the bicone direction out to ~2 kpc
radially, but also significantly extended in the direction of the cross-cone,
out to ~1.4 kpc. Our results suggest that the ratio of detected photons in the
cross-cone to the bicone region is ~16%, below 3 keV, decreasing to 5% for
energies 3-6 keV. The nuclear spectrum suggests a low photoionization phase
mixed with a more ionized gas component, while the bicone and cross-cone
spectra are dominated by a mix of photoionization and shocked gas emission. A
mixture of thermal and photoionization models to fit the spectra indicates the
presence of complex gas interactions, consistent with previous observations of
other CT AGN (e.g., ESO 428-G014).
