Black holes are extraordinarily dense objects possessing gravitational pulls so powerful even light cannot escape them. Supermassive black holes, which reside at the centre of many galaxies, including our own, are the largest of them

places at the centres of many large galaxies that have tremendous luminosity – sometimes outshining all of a galaxy's billions of stars combined – and produce the universe's most energetic outbursts seen since the Big Bang event 13.8 billion years ago. The energy arises from gas violently falling into a supermassive black hole that is surrounded by a cloud of tiny particles of rock and soot along with mostly hydrogen gas.