Physical Conditions and Extension of the Coronal Line Region in IC 5063

TL;DR

This study uses integral field spectroscopy to analyze the ionised and highly ionised gas in IC 5063, revealing extended coronal line emission, complex kinematics, and a strong link between coronal emission and the radio jet, providing new insights into AGN outflows.

Contribution

First detection of [Fe X] emission at large distances from the nucleus in an active galaxy, showing the relationship between coronal gas and radio jets in IC 5063.

Findings

Extended coronal emission up to 1.2 kpc from nucleus.

Coronal gas shows complex kinematics with high velocities.

Radio jet influences the properties and distribution of coronal gas.

Abstract

We study the ionised and highly ionised gas phases in the Seyfert~2 galaxy IC~5063 by means of VLT/MUSE integral field spectroscopy. Our analysis allowed us to detect a high-ionisation gas outflow traced by the coronal lines [\ion{Fe}{vii}]~$\lambda$6087 and [\ion{Fe}{x}]~$\lambda$6375. Both emissions are found to be extended. The former up to 1.2~kpc and 700~pc NW and SE from the nucleus, respectively. The latter reaches 700~pc NW of the nucleus. This is the first time that [\ion{Fe}{x}] emission is observed at such distances from the central engine in an active galactic nucleus. The [\ion{Fe}{vii}]~$\lambda$6087 emission peaks at the nucleus, with two secondary peaks at the position of the NW and SE radio-lobes. The gas kinematics is complex, with the coronal emission displaying split line profiles along the radio jet and line widths of several hundreds km~s$^{-1}$. Velocity shifts of up to 600~km~s$^{-1}$ in excess of the systemic velocity of the galaxy are found very close to the radio lobes and along the jet propagation. The extended coronal gas is characterised by temperatures reaching 20000~K and electron densities $>10^2$~cm$^{-3}$, with the larger values associated to the regions of larger turbulence, likely due to the passage of the radio jet. This hypothesis is supported by photoionisation models that combine the effects of the central engine and shocks. Our work highlights the strong relationship between extended coronal emission and the radio jet, with the former suitably tracing the latter, which in the case of IC~5063, propagates very close to the galaxy disc.