Chandra Detection of the Circumnuclear Molecular Torus of the Compton-thick Active Galactic Nucleus in NGC 5643

Abstract

We report a clumpy elongated feature found with deep Chandra Advanced CCD Imaging Spectrometer high-resolution imaging of the Fe K α line emission in the nuclear region of the Compton-thick active galactic nucleus galaxy NGC 5643. This feature extends for ∼65 pc north to south (N-S). No corresponding feature is seen in the 3.0–6.0 keV continuum. The Fe K α feature is spatially consistent with the N-S elongation found in the CO(2–1) high-resolution imaging with the Atacama Large Millimeter/submillimeter Array, but slightly more extended than the rotating molecular disk of diameter 26 pc indicated by the kinematics of the CO(2–1) line. The Chandra detection of a corresponding north to south structure in the neutral Fe K α line would argue for both CO and Fe K α emission originating from the obscuring torus.