Spatially Resolved [O III] Emission Line Kinematics of Reverberation-Mapped AGNs with the Keck Cosmic Web Imager

We present optical integral-field spectroscopic data of ten nearby ($0.02\le z\le 0.05$) Seyfert 1 galaxies taken with the Keck Cosmic Web Imager (KCWI). We map the spatially resolved kinematics of the [O III] gas and stars, and investigate the alignments between their global kinematic position angles (PA). Large-scale gas motions are primarily dominated by rotation, and are kinematically aligned with the stars ($\mathrm{\Delta }\text{PA}\le 30$ deg). However, eight galaxies exhibit non-rotational kinematic signatures (e.g., kinematic twists, possible outflows) in their ionized gas velocity fields near the nucleus. We compare aperture-wide measurements of the gas and stellar velocity dispersions (${\sigma }_{\text{gas}}$ and ${\sigma }_{\star }$) to test the use of the width of the [O III] line core as a surrogate for ${\sigma }_{\star }$. Direct comparisons between ${\sigma }_{\text{gas}}$ and ${\sigma }_{\star }$ show that ${\sigma }_{\text{gas}}$ tends to underestimate ${\sigma }_{\star }$, and thus is not a reliable tracer of ${\sigma }_{\star }$ for our selected galaxies. We measure the extent of the narrow-line region (NLR) using several definitions, resulting in sizes of $\sim 0.1$-$10$ kpc. For a given [O III] luminosity, our NLR sizes derived from the [O III]/H$\beta$ flux ratio or an [O III] isophotal radius are an order of magnitude larger than those measured from past imaging data.