Cygnus A: stars, dust and cones

We present new Hubble Space Telescope (HST) continuum and spectral line images of the radio galaxy Cygnus A. The images show much complex structure in the central kpc(2). Continuum images show the central dust lane in detail, allowing detailed maps of E(B-V) to be constructed; the dust appears to follow a roughly Galactic extinction law. The emission-line components are resolved in the line images and investigated in detail. A clear 'opening cone' morphology is found, especially in the lines of Hot and [O I]. Blue condensations are seen in the south-eastern emission component and surrounding the central region. These are almost certainly due to star formation, which began <1 Gyr ago as deduced from the colour of the regions. More extended blue continuum is also seen and corresponds to the blue polarized component detected by other recent spectropolarimetric observations.