Feedback from Mass Outflows in Nearby Active Galactic Nuclei. II. Outflows in the Narrow-Line Region of NGC 4151

TL;DR

This study analyzes the mass outflow rates and kinetic energy of ionized gas in the narrow-line region of NGC 4151, revealing significant feedback effects on galaxy evolution within about 100 parsecs of the SMBH.

Contribution

It provides a detailed methodology and measurements of outflow rates and energies in the NLR, highlighting the dominant role of in situ acceleration in AGN feedback.

Findings

Mass outflow rate peaks at 3 solar masses per year at 70 pc

Most outflow energy is deposited within 100 pc of the SMBH

NLR outflows exceed UV/X-ray absorber outflows in feedback significance

Abstract

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.