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6 hours ago
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If the thought of a supermassive black hole terrifies you, a new study may provide some relief.
Scientists say that these galactic giants might not actually be as big as we thought.
Researchers from the University of Southampton used a powerful new tool to measure the black hole at the core of an infant galaxy 12 billion light–years from Earth.
Their analysis revealed that this 'supermassive' black hole is actually 10 times smaller than expected.
The scientists say that earlier methods for measuring black holes haven't been accurately predicting the mass of these colossal voids.
That could mean scientists have overestimated the size of the biggest black holes in the universe for years.
'Our results suggest the methods to weigh these black holes used previously are just not working reliably in the early universe,' said co–author Professor Seb Hoenig.
'It could lead to a re–evaluation of our models of cosmic evolution.'
If the thought of a supermassive black hole terrifies you, a new study may provide some relief. Scientists say that these galactic giants might not actually be as big as we thought
Black holes are objects formed by the collapse of dying stars, so dense that not even light can escape their gravitational pull.
Scientists believe that supermassive black holes – black holes with a mass at least 100,000 times greater than the sun – formed very soon after the Big Bang.
Over the billions of years that followed, these early black holes grew to enormous sizes by feeding on gases and eventually gathered entire galaxies in their vast orbits.
However, scientists have struggled to understand how supermassive black holes grew to be so large so quickly.
Professor Hoenig says: 'We have been wondering for years how it's possible we discovered all these fully grown supermassive black holes in very young galaxies shortly after the Big Bang.
'They shouldn't have had the time to grow that massive.'
In a new study, published in the journal Astronomy and Astrophysics, Professor Hoenig and his co–authors argue that the answer is surprisingly simple: supermassive black holes aren't actually that big.
To reach this conclusion, the researchers focused on an ancient quasar – a black hole so distant and bright that it shines like a beacon from the dawn of the universe.
Supermassive black holes, like the one at the centre of our galaxy (pictured), formed early in the Universe's history and have grown to enormous sizes. However, in a new study, researchers say we have been overestimating their size
Researchers used a powerful new tool to peer into an infant galaxy 12 billion light–years from Earth, and measure the black hole at its core (pictured). This revealed that it was 10 times smaller than expected
Why are supermassive black holes smaller than expected?
Since black holes don't directly give off light, it's very difficult to accurately estimate their mass.
This is especially true of extremely distant black holes, which allow scientists to measure the conditions of the early universe.
Researchers now think that some black holes might have been producing huge jets of gas, ejected by powerful radiation.
These fast–moving jets could have tricked telescopes into thinking that the black hole was bigger than it really is.
By measuring how gases swirl around the edge of the black hole, scientists are now able to get a much closer estimate of the void's true size.
They measured this ancient light with a powerful new instrument called GRAVITY+.
Co–author Dr Taro Shimizu, of the Max–Planck Institute for Extraterrestrial Physics, told Daily Mail: 'GRAVITY+ combines the light from the four big telescopes on Paranal Observatory, which mimics the ability of a giant 100–meter telescope and allows for very precise measurements of the motion of the fast gas right near the supermassive black hole.
'By knowing both the location and speed of the gas, we can then exactly "weigh" the black hole.'
This new analysis revealed that the black hole was 800 million times the mass of the sun – which is still enormous, but 10 times smaller than the researchers had expected.
That huge difference suggests that the methods astronomers use to 'weigh' huge objects in space don't work reliably for these kinds of very old black holes.
Co–author Dr Richard Davies, also of the Max–Planck Institute for Extraterrestrial Physics, told Daily Mail: 'The previous estimates were based on locally measured relationships which might not work in the early universe.'
Dr Davies says the researchers still aren't sure why this is the case, but it could be because the black holes are giving out a lot more light than expected.
In addition to revealing the black hole's weight, the swirling gases in the galaxy's core also showed that this cosmic void was consuming gas at a rate much faster than had been thought possible.
The measurements used all four telescopes at the European Southern Observatory's 'Very Large Telescope' (pictured) to study the gases swirling around the black hole. This allowed for a more accurate measurement of the black hole's mass
That feeding frenzy is creating a huge outflow of gas, blasting out into space in a column travelling at speeds of 6,200 miles per second (10,000 km/s).
The researchers think that the intense radiation created by that outflow could have tricked telescopes into thinking the black hole was a lot bigger than in reality.
If other supermassive black holes in the early universe are also smaller than previously expected, it could have big consequences for our theories about the development of the universe.
Dr Davies adds: 'This is very significant, especially for understanding how galaxies and black holes grow and evolve.'
BLACK HOLES HAVE A GRAVITATIONAL PULL SO STRONG NOT EVEN LIGHT CAN ESCAPE
Black holes are so dense and their gravitational pull is so strong that no form of radiation can escape them - not even light.
They act as intense sources of gravity which hoover up dust and gas around them. Their intense gravitational pull is thought to be what stars in galaxies orbit around.
How they are formed is still poorly understood. Astronomers believe they may form when a large cloud of gas up to 100,000 times bigger than the sun, collapses into a black hole.
Many of these black hole seeds then merge to form much larger supermassive black holes, which are found at the centre of every known massive galaxy.
Alternatively, a supermassive black hole seed could come from a giant star, about 100 times the sun's mass, that ultimately forms into a black hole after it runs out of fuel and collapses.
When these giant stars die, they also go 'supernova', a huge explosion that expels the matter from the outer layers of the star into deep space.
