Interaction of the relativistic jet and the narrow-line region of PMN J0948+0022

TL;DR

This study reveals how the relativistic jet interacts with the narrow-line region in PMN J0948+0022, causing observable spectral changes and outflows, challenging previous classifications based solely on spectral profiles.

Contribution

It demonstrates that jet-NLR interaction can alter spectral line profiles, providing new insights into AGN structure and challenging the traditional view of Seyfert classifications.

Findings

Jet transfers energy to NLR, causing flux variations.

Spectral line profiles changed from Lorentzian to composite.

Evidence of outflows with velocities around 200 km/s.

Abstract

We have analyzed publicly available optical spectra of PMN J0948+0022 obtained with the Sloan Digital Sky Survey, X-Shooter, and the Multi Unit Spectroscopic Explorer (MUSE). Initially, PMN J0948+0022 was classified as a jetted narrow-line Seyfert 1 galaxy, but X-Shooter and MUSE observations, which have better spectral resolution, revealed a different profile for the H$\beta$ line, from Lorentzian to a composite one (a combination of a broad and a narrow Gaussian), more typical of intermediate Seyfert galaxies. According to the unified model, intermediate Seyferts are viewed at larger angles. However, we show that, in this case, the composite line profile results from the interaction of the powerful relativistic jet with the narrow-line region. The jet transfers part of its kinetic energy to the narrow-line region, producing flux changes in the H$\beta$ narrow component (drop by a factor of 3.4 from SDSS to X-Shooter), [O III]$\lambda$5007 core component (which nearly doubled from X-Shooter to MUSE), and its blue wing ($\Delta$v$\sim$200 km s$^{-1}$), which we interpret as evidence of an outflow. We also recalculated the physical parameters of this AGN, obtaining a black hole mass of $10^{7.8}$ M$_{\odot}$ and an Eddington ratio of $\sim$0.21 (weighted mean).