1996A&A...307L..29J

We present a new HST image of Cygnus A, taken in the V-band. This image includes both continuum and lines of [0III], and shows the major, northwestern and southeastern components, together with the weaker central component. Filamentary structure is present at this resolution of 0.045". This structure runs generally parallel to the radio jet and may be due to mechanical excitation of the gas in shocked regions, possibly combined with photoionization by a hidden quasar like nucleus. The image shows clearly the reddened region near the centre seen by other authors. The darker region within the northwestern component, previously claimed to be a result of passage of the radio jet, is more likely to be a result of dust obscuration. The central component is extended and bears some resemblance to the apex of a conical structure; similar structures in other galaxies have been claimed as evidence for light from a hidden nucleus escaping along a restricted range of solid angle. In addition, a number of blobs and condensations are seen within all the above structures, some of which may be stellar in origin.