A Deep Chandra ACIS Study of NGC 4151. II. The Innermost Emission Line
  Region and Strong Evidence for Radio Jet-NLR Cloud Collision
  We have studied the X-ray emission within the inner 150 pc radius of NGC 4151
by constructing high spatial resolution emission line images of OVII, OVIII,
and NeIX. These maps show extended structures that are spatially correlated
with the radio outflow and optical [OIII] emission. We find strong evidence for
jet--gas cloud interaction, including morphological correspondences with
regions of X-ray enhancement, peaks of near-infrared [FeII] emission, and
optical clouds. In these regions, moreover, we find evidence of elevated
NeIX/OVII ratios; the X-ray emission of these regions also exceeds that
expected from nuclear photoionization. Spectral fitting reveals the presence of
a collisionally ionized component. The thermal energy of the hot gas suggests
that >0.1% of the estimated jet power is deposited into the host interstellar
medium through interaction between the radio jet and the dense medium of the
circum-nuclear region. We find possible pressure equilibrium between the
collisionally ionized hot gas and the photoionized line-emitting cool clouds.
We also obtain constraints on the extended iron and silicon fluorescent
emission. Both lines are spatially unresolved. The upper limit on the
contribution of an extended emission region to the Fe Kalpha emission is <5% of
the total, in disagreement with a previous claim that 65% of the Fe Kalpha
emission originates in the extended narrow line region.
