What is a radio galaxy?
Galaxies contain billions and billions of stars just like our sun. At night we can see the galaxy that we live in stretching across the sky – we call it the Milky Way. Many galaxies contain massive black holes at their centres, sometimes weighing billions of times more than our sun. In some galaxies these black holes are sucking in the material around them, spinning it up fast and then squirting it away from the black hole at close to light speed, as a jet. These jets produce radio waves that radio telescopes like the one that was operating at Dover Heights can detect – galaxies such as these are called radio galaxies.