ABSTRACT
The opening up of the whole electromagnetic spectrum to astronomical observations in the post-war years led to several exciting and unexpected discoveries that exceeded the hopes even of the pioneering scientists involved and took astronomy into a new era. In the early post-war years, it was not anticipated that there would be any significant emissions from celestial bodies in X-rays, and this region was only opened up after unexpected clues to its importance were afforded. The first great post-war discovery occurred in the early 1960s when the very first quasar – a new and very different kind of galaxy – was located and identified. The central black hole cores contain about a thousand million solar masses or about 1 per cent of the mass of our Milky Way galaxy. The light beam was being bent around one side of the intervening galaxy by its gravitational field and around the other side, each producing an image slightly displaced from the other.
