High-resolution imaging from Mauna Kea : Cygnus A.

A high-resolution image of Cygnus A was obtained using a computer-controlled active-mirror autoguider. The CCD image, with FWHM = 0.65 arcsec, reveals considerable structure in the central 2 kpc of Cygnus A: an elliptically shaped region that contains the central radio source, a concentrated knot that looks like an extra galaxy nucleus (which appears in the projection within 900 h(-1) pc of the central radio component), and some indication that the central region around the radio source contains a patchy dust distribution. As originally suggested by Baade and Minkowski (1954), Cygnus A is best described as a collision of galaxies. With the improved resolution, Cygnus A shows only cursory resemblance to Centaurus A.