Gas inflows towards the nucleus of NGC1358

TL;DR

This study uses optical integral field spectroscopy to analyze gas kinematics in NGC1358, revealing inflows, outflows, and feedback processes that influence the galaxy's active nucleus and gas dynamics.

Contribution

It provides detailed kinematic analysis of gas inflows and outflows in NGC1358, highlighting the role of nuclear spirals and AGN feedback in galaxy evolution.

Findings

Detected five gaseous kinematic components.

Estimated mass inflow rate of ~0.015 M_sun/yr.

Identified nuclear spiral arms with inflow and outflow motions.

Abstract

We use optical spectra from the inner 1.8 $\times$ 2.5kpc$^2$ of the Seyfert 2 galaxy NGC1358, obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of $\approx$ 165pc, to assess the feeding and feedback processes in this nearby active galaxy. Five gaseous kinematical components are observed in the emission line profiles. One of the components is present in the entire field-of-view and we interpret it as due to gas rotating in the disk of the galaxy. Three of the remaining components we interpret as associated to active galactic nucleus (AGN) feedback: a compact unresolved outflow in the inner 1 arcsec and two gas clouds observed at opposite sides of the nucleus, which we propose have been ejected in a previous AGN burst. The disk component velocity field is strongly disturbed by a large scale bar. The subtraction of a velocity model combining both rotation and bar flows reveals three kinematic nuclear spiral arms: two in inflow and one in outflow. We estimate the mass inflow rate in the inner 180pc obtaining $\dot{M}_{in}$ $\approx$ 1.5 $\times 10^{-2}$M$_{\odot}$yr$^{-1}$, about 160 times larger than the accretion rate necessary to power this AGN.