Active Galactic Nuclei and STaR fOrmation in Nearby Galaxies AGNSTRONG. III. A Study on Ionized and Warm Molecular Gas Outflows of 6 Type-2 AGNs

Active galactic nucleus (AGN)-driven gas outflows are one of the best tracers of AGN feedback in action, as these powerful outflows expel/heat or compress the surrounding interstellar medium (ISM), thus quenching or enhancing star-forming activity in their hosts. Studying the kinematics of outflows in different gas phases is crucial for comprehending how AGNs impact the ISM within their host galaxies. However, the differences in the physical natures of ionized and warm molecular gas outflows remain largely unexplored. To obtain a complete picture of AGN outflows and their feedback effects, we present a study of both ionized and warm molecular gas outflows in six type-2 AGNs ($z<0.1$) that exhibit strong ionized outflows in previous optical observations. Utilizing the Triple Spectrograph and Double Spectrograph instruments on the Palomar 200-inch Hale Telescope, we conduct spatially resolved measurements in the slit direction of strong emission lines from both ionized and warm molecular gas, such as $\rm [O\ III]$, $\rm Paα$, $\rm H_{2}$ 1-0 S(1), etc., allowing for a direct comparison of their outflow properties. One out of six AGNs shows significant ionized and warm molecular outflows in near-infrared bands, exhibiting the most powerful kinematics and highest luminosity. A positive correlation between the kinematics and AGN luminosity is shown, suggesting that more luminous AGNs, which reflect higher levels of AGN activity, tend to have a greater impact on the gases, probably driving the outflows.

💡 Research Summary

This paper presents a detailed comparative study of ionized‑gas and warm‑molecular‑gas outflows in six nearby (z < 0.1) type‑2 active galactic nuclei (AGNs) that were previously identified as having extreme ionized outflows. Using the Triple Spectrograph (TPSP) and Double Spectrograph (DBSP) on the Palomar 200‑inch telescope, the authors obtained spatially resolved slit spectra covering key emission lines: