Feedback from Mass Outflows in Nearby Active Galactic Nuclei. II.
  Outflows in the Narrow-Line Region of NGC 4151
  We present a detailed study of AGN feedback in the narrow-line region (NLR)
of the Seyfert 1 galaxy NGC 4151. We illustrate the data and techniques needed
to determine the mass outflow rate and kinetic luminosity of the outflowing
ionized gas as a function of position in the NLR. We find that the mass outflow
rate peaks at a value of 3 solar masses per year at a distance of 70 pc from
the central supermassive black hole (SMBH), which is about 10 times the outflow
rate coming from inside 13 pc, and 230 times the mass accretion rate inferred
from the bolometric luminosity of NGC 4151. Thus, most of the outflow must
arise from "in situ" acceleration of ambient gas throughout the NLR. The
kinetic luminosity peaks at 90 pc and drops rapidly thereafter, indicating that
most of the kinetic energy is deposited within about 100 pc from the SMBH. Both
values exceed the mass outflow rate and kinetic luminosity determined for the
UV/X-ray absorber outflows in NGC 4151, indicating the importance of NLR
outflows in providing feedback on scales where circumnuclear star formation and
bulge growth occur.
