Active galaxies. Coloured Chandra X-ray Telescope image of distant active galaxies and quasars in the constellation Fornax. This image, the Chandra Deep Field South, records X-rays emitted by active galaxies and quasars that are powered by massive black holes. Quasars are thought to be young versions of active galaxies. These astronomical objects are located up to 12 billion light years from Earth. The energies of the objects are colour-coded, from red (lowest) to blue (highest). The image was made by the Advanced CCD Imaging Spectrometer (ACIS).