Unraveling the Complex Structure of AGN-driven Outflows. III. The Outflow Size-Luminosity Relation

Energetic gas outflows driven by active galactic nuclei (AGNs) are considered as one of the mechanisms by which supermassive black holes affect their host galaxies. To probe the impact of AGN-driven outflows, it is essential to quantify the size of the region under the influence of such outflows. In the third of a series of papers, we present the spatially resolved kinematics of ionized gas for three additional Type 2 AGNs based on Gemini Multi-Object Spectrograph (GMOS) integral field spectroscopy. Along with the six AGNs presented in our previous works and the 14 AGNs with available GMOS-integral field unit data, we construct a sample of 23 luminous Type 2 AGNs at z < 0.2, and kinematically measure the size of ionized gas outflows by tracing the radial decrease of the velocity dispersion of the [O iii] λ5007 emission line. The kinematically measured outflow size ranges from 0.60 to ∼7.45 kpc, depending on AGN luminosity. We find that the size of the photoionized region is larger than the kinematically measured outflow size, while the flux-weighted photoionization size is significantly smaller. Thus, using photoionization size as a proxy for outflow size leads to overestimation or underestimation, and introduces large uncertainties of the mass outflow rate and the energy output rate. We report an outflow size-luminosity relation with a slope of 0.28 0.03, which is shallower than the slope of the correlation between the photoionization size and luminosity.