The awe-inspiring power of black holes is so flabbergasting it’s often hard to put into words.
So we’re very glad that Chinese astronomers have issued their own startling description of these cosmic monsters.
A team of stargazers from the People’s Republic have described how a certain type of black hole behaves like a ‘starved space dragon’.
The scientists have published a new piece of research exploring quasars, which are the ‘universe’s brightest beacons’ and often shine more luminously than entire galaxies.
It’s believed quasars are powered by an ‘all-consuming’ black hole which is munching on an ‘accretion disc’ of gas and material surrounding it, causing it to glow incredibly brightly.
‘As the most luminous steady beacons in the Universe, quasars are believed to be powered by an accretion disk around the central black hole,’ said Hongyan Zhou, faculty member at the University of Science and Technology of China.
‘The supermassive black hole in the centre of the quasar gobbles up an enormous amount of nearby materials, which glare and shine when they constitute an accretion disk before finally sliding down in the black hole.
‘Outside the accretion disk, materials are continuously pumped from all directions to the center by the centre feed the black hole with an endless appetite.’
Zhou also compared the black hole of a quasar to a dragon.
It’s impossible to see what’s going on at the centre of a quasar, because of the sheer brightness of the accretion disc as it’s munched up by its black hole.
But it’s believed the gas swirls faster and faster as it approaches the hole, rather like water swirling around the plughole of a bath.
The Chinese scientists used a phenomenon called the doppler effect to measure the speed of the gas going into the black hole.
Here on Earth, you can hear this effect in action when a police car speeds past and its siren appears to drop in pitch as it drives away.
The team measured the gas moving at a whopping 5,000 kilometres a second.
‘Such a high velocity can only be accelerated by the strong gravity of the central black hole,’ Zhou added.
‘It’s comparable to how, in a meteor shower, the closer the meteors get to the ground, the faster they fall.’
In the quasars Zhou observed, the accretion disks were fed with ‘fast-falling external mass from surrounding space’ – which basically means anything unlucky enough to be nearby.
These discs then feed the black hole and make the quasar shine.