Spatially-resolved spectroscopy of narrow-line Seyfert 1 host galaxies

TL;DR

This study uses spatially-resolved spectroscopy to analyze the host galaxies of five narrow-line Seyfert 1 galaxies, revealing star formation activity, gas kinematics, and metallicity at large scales, providing insights into their galaxy-AGN relationship.

Contribution

First spatially-resolved spectroscopic analysis of NLS1 host galaxies at 2-3 kpc scales, separating AGN and host contributions to understand galaxy properties.

Findings

Host galaxy gas shows large-scale rotation.

Gas ionized mainly by star formation, not AGN.

Star formation rates are mostly below or on the main sequence.

Abstract

We present optical integral field spectroscopy for five $z<0.062$ narrow-line Seyfert 1 galaxies (NLS1s) host galaxies, probing their host galaxies at $\gtrsim 2-3$ kpc scales. Emission lines in the nuclear AGN spectra and the large-scale host galaxy are analyzed separately, based on an AGN-host decomposition technique. The host galaxy gas kinematics indicates large-scale gas rotation in all five sources. At the probed scales of $\gtrsim 2-3$ kpc, the host galaxy gas is found to be predominantly ionized by star formation without any evidence of a strong AGN contribution. None of the five objects shows specific star formation rates exceeding the main sequence of low-redshift star forming galaxies. The specific star formation rates for MCG-05-01-013 and WPVS 007 are roughly consistent with the main sequence, while ESO 399-IG20, MS 22549-3712, and TON S180 show lower specific star formation rates, intermediate to the main sequence and red quiescent galaxies. The host galaxy metallicities, derived for the two sources with sufficient data quality (ESO 399-IG20 and MCG-05-01-013), indicate central oxygen abundances just below the low-redshift mass-metallicity relation. Based on this initial case study, we outline a comparison of AGN and host galaxy parameters as a starting point for future extended NLS1 studies with similar methods.