False-colour optical image of the radio galaxy Centaurus A (NGC 5128),showing the great lane of dust which bisects it. Centaurus A is basically a giant elliptical galaxy encircled by a rotating disc of gas and dust which,seen edge-on,forms the dust lane. Radio maps reveal two enormous radio lobes extending fully 10 degrees across the sky and lying at right angles to the dust lane. A giant cluster of hot stars and gas,more luminous than many entire galaxies,lies at the galaxy's centre. Within this,so many astronomers believe,is a black hole,the central "engine" powering the galaxy. Located some 16 million light years away,Centaurus A is the nearest active galaxy to Earth |