Figure 13-53 Cygnus A (3C 405) (a) Radio image produced from observations made at the Very Large Array. Most of the radio emissions from Cygnus A come from the radio lobes located on either side of the peculiar galaxy seen in the inset, a Hubble Space Telescope image. Each of the two radio lobes extend about 160,000 ly from the optical galaxy and contain a brilliant, condensed region of radio emission. Inset: At the heart of this system of gas lies a strange-looking galaxy that has a redshift that corresponds to a recessional speed of 5% of the speed of light. According to the Hubble law, Cygnus A is therefore 635 million ly from Earth. Because Cygnus A is one of the brightest radio sources in the sky, this remote galaxy’s energy output must be enormous. (b) An X-ray image of Cygnus A taken by the Chandra X-ray Observatory showing that some of the jet particles from the central source have spread throughout the galaxy and, striking other gas and dust, caused this debris to heat and emit X-rays.