CHEERS Results from NGC 3393, II: Investigating the Extended Narrow Line Region using Deep Chandra Observations and Hubble Narrow Line Imaging

TL;DR

This study uses high-resolution X-ray and optical imaging to analyze the complex, multi-phase extended narrow line region in NGC 3393, revealing stratified ionization, shock contributions, and filamentary structures influenced by AGN outflows.

Contribution

It provides the first detailed multiwavelength analysis of the ENLR in NGC 3393, highlighting the stratified ionization and shock effects in the AGN feedback process.

Findings

ENLR is a multi-phase, stratified structure within 50 pc of the nucleus.

Shocks contribute to gas compression and ionization in the outflow regions.

Filamentary X-ray and optical structures suggest an undetected plasma component.

Abstract

The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGN) designed to take full advantage of Chandra's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble narrow line images of [O III], [S II] and H$\alpha$, as well as previously-unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms which envelope the nuclear radio outflows extend only $\lesssim$0.2'' ($\lesssim50 pc$) across. The high-resolution multiwavelength data suggest that the ENLR is a complex multi-phase structure in the circumnuclear ISM. Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ~10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include H$\alpha$ evidence for gas compression and extended MUV emission, and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.