A 700 pc Extended Coronal Gas Emission in the Circinus Galaxy

We report the first characterization of an extended outflow of high ionized gas in the Circinus Galaxy by means of the coronal line (CL) [Fe vii] λ6087. This emission is located within the ionization cone already detected in the [O iii] λ5007 line and is found to extend up to a distance of ∼700 pc from the active galactic nucleus. The gas distribution appears clumpy, with several knots of emission. Its kinematics is complex, with split profiles and line centroids shifted from the systemic velocity. The physical conditions of the gas show that the extended coronal emission is likely the remnant of shells inflated by the passage of a radio jet. This scenario is supported by extended X-ray emission, which is spatially coincident with the morphology and extension of the [Fe vii] λ6087 gas in the NW side of the galaxy. The extension of the coronal gas in the Circinus galaxy is unique among active galaxies and demonstrates the usefulness of CLs for tracing the shock ionization component in these objects.