Deep Chandra Observations of ESO 428-G014: III. High Resolution Spectral Imaging of the Ionization Cone and Radio Jet Region

TL;DR

Deep Chandra observations of ESO 428-G014 reveal complex X-ray morphology, ionization processes, and interactions between jets and molecular clouds, providing insights into the structure of this Compton Thick AGN.

Contribution

This study provides high-resolution spectral imaging of the ionization cone and radio jet region in ESO 428-G014, highlighting localized absorption, emission processes, and the impact of extended emission on spectral modeling.

Findings

Extended emission accounts for 70-30% of central X-ray counts.

Collisional ionization is prevalent in regions of intense optical emission.

Extended emission may bias torus spectral models in lower-resolution X-ray observations.

Abstract

We have analyzed the deep Chandra observation (~155 ks) of the Compton Thick Active Galactic Nucleus (CT AGN) ESO 428-G014, to study in detail the morphology of the diffuse X-ray emission in the inner ~500 pc radius region. Comparing different X-ray energy bands we find localized differences in the absorbing column and in the emission processes. Collisional ionization may be prevalent in the area of most intense optical line emission (Halpha and [OIII]). There is a good correspondence between optical line, radio continuum and soft (<3 keV) X-ray features, consistent with simulations of jet/molecular disk interactions. At all energies >3 keV, the extended emission in the central 1".5 (170 pc) radius circumnuclear region amounts to ~70-30% of the contribution of a point source in that area (or 40-25% of the total counts in the region). Within a 5" radius, the contribution from extended emission overcomes that from a nuclear point source in the 3-4 keV band. This extended emission suggests scattering of nuclear photons by dense molecular clouds in the inner galactic disk of ESO 428-G014. Its presence may adversely bias the torus modeling of spectra from X-ray telescopes with inferior angular resolution than Chandra, such as NuSTAR and XMM-Newton.