Astronomers have discovered the oldest supermassive black hole yet – almost dating back to the time of the Big Bang.
The black hole, which is an estimated 10 to 100 million times more massive than our sun, is 13.2 billion light-years away in the galaxy UHZ-1.
This means its light has travelled 13.2 billion years to reach our space telescopes – making it an astonishing snapshot of the ancient past.
It also means it formed just 500 million years after the Big Bang (13.7 billion years ago), when the universe was only three per cent of its current age.
Although it’s not one of the most massive black holes ever, it’s unusually huge for such an early stage of growth and was ‘born massive’, researchers say.
Astronomers found the most distant black hole ever detected in X-rays using the Chandra and James Webb space telescopes. X-ray emission is a telltale signature of a growing supermassive black hole. These images show the galaxy cluster Abell 2744 that UHZ1 is located behind, in X-rays from Chandra and infrared data from Webb, as well as close-ups of the black hole host galaxy UHZ1
James Webb Space Telescope (JWST) images taken of the galaxy UHZ-1 using the observatory’s NIRCam
Precisely how the first black holes were formed in the universe’s infancy has been a long-standing debate among astronomers.
But the fact this black hole is so old while having such a large mass gives astronomers a crucial clue.
Researchers think it directly formed from the collapse of a huge cloud of gas, based on X-rays detected by telescopes including James Webb.
‘Finally discovering a black hole that was so large, when the universe was so young, tells us that the black hole must have been very large when it was initially formed, probably from the direct collapse of a massive gas cloud,’ said study author Andy Goulding at Princeton University in New Jersey.
‘The black hole has only a very short time to grow, which means that either it grew extraordinarily fast or the black hole was simply born larger.’
Famously an inspiration for sci-fi movies, 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 dust and gas, as well as planets and even other black holes.
They are often described as ‘destructive monsters’ because they tear apart stars, consuming anything that comes too close, and hold light captive.
Black holes act as intense sources of gravity that hoover up surrounding dust and gas, as well as planets and even other black holes (artist’s depiction)
Researchers found the black hole using NASA’s Chandra X-ray Observatory and NASA’s James Webb Space Telescope (depicted here)
A supermassive black hole is the largest type of black hole, with a mass more than 100,000 and up to 10 billion times the mass of our sun.
Researchers estimated that this particular black hole’s mass is between 10 and 100 million suns based on the brightness and energy of X-rays.
This mass is similar to that of all the stars in the galaxy where it lives – but this is something of an astronomical oddity.
Usually, black holes in the centres of other galaxies contain only about a tenth of a percent of the mass of their host galaxy’s stars.
The research team detected the X-rays using two NASA space telescopes – James Webb, the most powerful space telescope of all which can ‘peer back through time’, and the quarter-century old Chandra observatory.
Chandra, launched in 1999, is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope.
‘We needed Webb to find this remarkably distant galaxy and Chandra to find its supermassive black hole,’ said study author Akos Bogdan at the Center for Astrophysics in Cambridge, Massachusetts.
Chandra images showed the presence of intense, superheated, X-ray emitting gas in this galaxy – a trademark for a growing supermassive black hole
Two weeks of observations with Chandra showed the presence of intense, superheated, X-ray emitting gas in this galaxy – a trademark for a growing supermassive black hole.
The team were aided by a magnifying effect known as gravitational lensing – where one massive object’s gravitational field magnify and distort the light coming from another object behind it.
Light from the galaxy and the X-rays from gas around the black hole were magnified by about a factor of four by ‘intervening matter’ due to gravitational lensing.
This had the effect of enhancing the infrared signal detected by Webb and allowing Chandra to detect the faint X-ray source.
Overall, the findings agree with predictions in 2017 for an ‘outsize black hole’ that directly formed from the collapse of a huge cloud of gas, according to the team.
‘The combination of such a high black hole mass and large black hole-to-galaxy stellar mass ratio just 500 million years after the Big Bang was theoretically predicted,’ they say.
Chandra, launched in 1999, is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope
They believe other theories of how black holes form, like the death of the first massive stars, can be ruled out because those couldn’t produce a black hole large enough to explain this one.
The researchers plan to use this and other results from Webb and data from other telescopes to fill out a larger picture of the early universe.
‘Data from JWST is rapidly transforming our understanding of the early universe by enabling the detection of large samples of faint, distant galaxies deep into the epoch,’ they conclude.
The study has been published in the journal Nature Astronomy.
