Spatially Resolved, Multiphase Mass Outflows of the Seyfert 1 Galaxy NGC 3227

TL;DR

This study measures and compares ionized, warm, and cold molecular gas outflows in NGC 3227, revealing their spatial distribution, rates, and impact on clearing the galaxy's central gas over millions of years.

Contribution

First spatially resolved measurements of multi-phase gas outflows in NGC 3227, linking outflow rates to gas evacuation timescales and AGN duty cycle.

Findings

Ionized outflow rate peaks at 19.9 M_sun/yr near 47 pc from SMBH.

Warm molecular outflow rate is ≤ 9 x 10^{-4} M_sun/yr at 36 pc.

Cold molecular outflow rate is ≤ 23.1 M_sun/yr at 57 pc.

Abstract

We present spatially resolved mass outflow rates of the ionized and molecular gas in the narrow line region of the Seyfert 1 galaxy NGC 3227. Using long-slit spectroscopy and [O III] imaging from from Hubble Space Telescope's Space Telescope Imaging Spectrograph and Apache Point Observatory's Kitt Peak Ohio State Multi-Object Spectrograph, in conjunction with Cloudy photoionization models and emission line diagnostics, we find a peak ionized mass outflow rate of $\dot M_{\text{ion}} =$ $19.9\pm9.2$ M$_\odot$ yr$^{-1}$ at a distance of $47\pm6$ pc from the supermassive black hole (SMBH). Using archival data from the Gemini-North Near-infrared Field Spectrograph measuring H$_2$ $\lambda2.1218$ $\mu$m emission, we find a maximum peak warm molecular outflow rate of $\dot M_{\mathrm{H_2}} \le 9 \times 10^{-4}$ M$_\odot$ yr$^{-1}$ at a distance of $36\pm6$ pc from the SMBH. Using archival data from the Atacama Large Millimeter/submillimeter Array measuring CO(2-1) emission, we find a maximum peak cold molecular gas mass outflow rate of $\dot M_{\mathrm{CO}} \le$ $23.1$ M$_\odot$ year$^{-1}$ at a distance of $57\pm6$ pc from the SMBH. For the first time, we calculate spatially resolved gas evacuation timescales for the cold molecular gas reservoirs ostensibly sourcing the outflows, and find that evacuating gas to $\sim$400 pc from the SMBH occurs on timescales of $10^{6.0} - 10^{7.6}$ years. These results indicate that the multi-phase AGN outflows are effective in clearing the inner few hundred parsecs of NGC 3227's gas content on timescales that may set the AGN duty cycle of $10^5 - 10^8$ years.