High-resolution mid-infrared morphology of Cygnus A

We present sub-arcsecond resolution mid-infrared images at 10.8 and 18.2 microns of Cygnus A. These images were obtained with the University of Florida mid-IR camera/spectrometer, OSCIR, at the Keck II 10 m telecope. Our data show extended mid-IR emission primarily to the east of the nucleus with a possible western extension detected after image deconvolution. This extended emission is closely aligned with the bi-cone observed at optical and near-IR wavelengths by HST. This morphology is consistent with warm dust destruction within the bi-cone, possibly due to outflows from the central quasar which also may cause a density enhancement along the walls of the ionization cone. Additionally, we also marginally detect large-scale low-level emission extending > 1.5 kpc from the nucleus.