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 active galactic nucleus 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 ((M) over dot(out)) and kinetic luminosity (L-KE) of the outflowing ionized gas as a function of position in the NLR. We find that (M) over dot(out) peaks at a value of 3.0 M-circle dot yr(-1) 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. L-KE 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 (M) over dot(out) and L-KE 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.