Probing AGN-ISM Feedback through Extended X-ray Emission in ESO 137-G034
D. Ł. Król, G. Fabbiano, M. Elvis, A. Trindade Falcão, R. Middei, D. Rosario, R. Davies, T. Shimizu, D. Hill
TL;DR
The study investigates how AGN feedback couples to the ISM in a nearby Compton-thick AGN by exploiting deep Chandra X-ray observations to map and spectrally decompose extended emission along the [O III] bi-cone and across the cross-cone. Spatially resolved spectroscopy reveals that the extended X-ray emission cannot be described by photoionized gas alone and requires a thermal, shock-heated component, consistent with both radiative and mechanical feedback from the AGN. The authors find evidence for jet-ISM interactions, including a possible thermal component at the SE jet termination and asymmetric behavior in the SE versus NW cones, as well as soft X-ray emission in the cross-cones indicative of jet-induced shocks in a clumpy ISM. Overall, the results underscore the combined role of radiative winds and jet-driven shocks in shaping the circumnuclear environment of ESO 137-G034 and highlight the importance of multi-wavelength morphology in understanding AGN feedback in CT systems.
Abstract
We present a detailed analysis of the X-ray emission of the Compton-thick (CT) AGN ESO 137-G034 based on deep ($\sim230$ ks) Chandra observations. As in other CT AGNs, the morphology of the emission is elongated, approximately following the [O III] ionization bicone. With spatially resolved spectral modeling, we show that the extended emission within the bi-cone regions { is most readily explained} as from a mixture of photo-ionized gas and shock-heated plasma, reflecting the combined effects of radiative and kinematic AGN feedback. By comparing the morphology of the { X-ray emission in narrow spectral bands and that of the 3 cm radio jet, we find suggestive evidence of thermal, possibly shocked emission associated with the SE termination of the radio jet. This interpretation is also supported by the lack of [O III] relative to the $0.3-3.0$ keV flux in the inner $3^{\prime\prime}$ ($\sim600$ pc) of the SE cone, which would be consistent with an additional thermal X-ray component on top of the photonized emission of an outflowing wind. A similar effect is only seen within the inner $1^{\prime\prime}$ ($200$ pc) of the NW cone. In the radial profile of the [OIII]/X-ray flux ratio and the X-ray hardness ratio within the inner $\sim3^{\prime\prime}$ ($\sim600$ pc) of the SE cone we see an asymmetry, with no counterpart in the NW cone. We detect soft extended X-ray emission in the cross-cones which may originate from the interaction of an embedded radio jet with a clumpy interstellar medium (ISM). }These results highlight the { importance of both} radiative and mechanical feedback in shaping the circumnuclear environment of ESO 137-G034.