They’re probably the most feared objects in the universe – huge concentrations of tightly-packed matter that can gobble up entire planets.
Now, a stunning 3D map shows 1.3 million supermassive black holes living at the centres of other galaxies in the universe.
In the map, each black hole appears as a tiny red dot, almost like a liquid particle in a plume of colourful vapour.
But in reality each one has a mass millions to billions of times the mass of the sun and resides thousands of light years away.
Researchers stress that this map doesn’t show all the black holes in the observable universe – a figure that’s thought to reach a mind-boggling 40 quintillion.
The map was created by an international team of astronomers led by David Hogg, a professor of physics and data science at New York University, using data from the Gaia spacecraft.
‘Each point in that diagram represents a supermassive black hole at the centre of a galaxy, with the colour telling you how close or far away they are from us – yellow is closer, blue is farther,’ he told MailOnline.
Famously an inspiration for sci-fi movies like ‘Event Horizon’, black holes are regions of spacetime where gravity’s pull is so strong that even light can not get out.
They act as intense sources of gravity that hoover up surrounding matter like dust and gas, as well as planets and even other black holes.
The new map specifically shows ‘quasars’ – supermassive black holes that are actively feeding on material and emit electromagnetic radiation, becoming incredibly bright and luminous.
‘There are lots of black holes – every reasonably big galaxy probably has one at its centre,’ Dr Christopher Onken, an astrophysicist at Australian National University in Canberra, who wasn’t involved in the map.
‘But most of them aren’t quasars because they’re not eating enough material,’ he told MailOnline.
‘When there’s plenty of material near a black hole, the matter flattens down into a pancake shape and heats up to such high temperatures that it glows brightly enough to be seen far, far away, and then we call it a quasar.
‘So the black hole is basically the heart of the quasar.’
The new map logs the location of about 1.3 million quasars in space and time, the furthest of which shone bright when the universe was only 1.5 billion years old.
For comparison, the universe is now 13.7 billion years old.
The scientists built the map using data from the European Space Agency’s Gaia space telescope, which is around 930,000 miles (1.5 million km) away from Earth.
While Gaia’s main objective is to map the stars in our galaxy, it also inadvertently spots objects outside the Milky Way, such as quasars and other galaxies.
The team used data from Gaia’s third data release, which contained 6.6 million quasar candidates, and data from NASA’s Wide-Field Infrared Survey Explorer and the Sloan Digital Sky Survey.
By combining the datasets, the team removed ‘contaminants’ such as stars and galaxies from Gaia’s original dataset and more precisely pinpointed the distances to the quasars.
They also mapped where dust, stars and other ‘nuisances’ are expected to block our view of certain quasars, which is critical for interpreting the quasar map.
‘This quasar catalog is a great example of how productive astronomical projects are,’ said Professor Hogg.
‘Gaia was designed to measure stars in our own galaxy, but it also found millions of quasars at the same time, which give us a map of the entire universe.’
Astronomers say the locations of distant black holes and their host galaxies can help them better understand how the cosmos expanded over time.
Most, if not all, galaxies possess monstrous black holes at their cores, including our own Milky Way galaxy.
When galaxies merge, their black holes ‘sink’ to the middle of the newly formed galaxy and eventually join together to form an even more massive black hole.
As the black holes spiral toward each other, they increasingly disturb the fabric of space and time, sending out gravitational waves, which were first predicted by Albert Einstein more than 100 years ago.
Professor Hogg and his colleagues present the map in a paper published in The Astrophysical Journal.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
