Feeding and Feedback in NGC3081

TL;DR

This study maps the gas kinematics in NGC3081, revealing bipolar outflows and potential inflows, providing insights into the feeding and feedback processes near the galaxy's nucleus.

Contribution

First detailed two-dimensional gas kinematic analysis of NGC3081, identifying outflows and inflows linked to nuclear activity and galaxy structure.

Findings

Detected bipolar outflows with mass outflow rates of 1.9-6.9 x 10^{-3} M_sun/yr.

Identified non-circular gas motions possibly indicating inflows of ~1.3 x 10^{-2} M_sun/yr.

Mapped complex gas dynamics associated with nuclear activity and galaxy morphology.

Abstract

We present two-dimensional gaseous kinematics of the inner 1.2 $\times$ 1.8 kpc$^2$ of the Seyfert 2 galaxy NGC3081, from optical spectra (5600--7000\r{A}) obtained with the GMOS integral field spectrograph on the Gemini North telescope at a spatial resolution of $\approx$ 100pc. We have identified two-components in the line emitting gas. A narrower component (FWHM $\approx$ 60-100km s$^{-1}$), which appears to be gas in the galaxy disk, and which shows a distorted rotation pattern, is observed over the whole field of view. A broader component (FWHM $\approx$150-250 km s$^{-1}$) is present in the inner $\approx$ 2arcsec (200pc) and shows blueshifts and redshifts in the near and far sides of the galaxy, respectively, consistent with a bipolar outflow. Assuming this to be the case, we estimate that the mass outflow rate in ionized gas ($\dot{M}_{out}$) is between 1.9 $\times 10^{-3}$M$_{\odot}$ yr$^{-1}$ and 6.9 $\times 10^{-3}$M$_{\odot}$ yr$^{-1}$. The subtraction of a rotation model from the narrower component velocity field reveals a pattern of excess blueshifts of $\approx$ 50km s$^{-1}$ in the far side of the galaxy and similar excess redshifts in the near side, which are cospatial with a previously known nuclear bar. We interpret these residuals as due to gas following non-circular orbits in the barred potential. Under the assumption that these motions may lead to gas inflows, we estimate an upper limit for the mass inflow rate in ionized gas of $\phi$ $\approx$ 1.3 $\times 10^{-2}$M$_{\odot}$ yr$^{-1}$.