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Hubble spots the 'ancestor of a supermassive black hole'

Hubble spots the 'ancestor of a supermassive black hole'

Astronomers believe they have identified the ancestor of a supermassive black hole that was born relatively soon after the Big Bang 13.8 billion years ago.

Simulations had shown such objects to exist, but experts say this is the first real find.

The distant object, which has properties intermediate between those of a galaxy and a quasar, was discovered using the iconic Hubble Space Telescope.

With its location in space — undisturbed by weather changes and pollution — the 32-year-old observatory can see further into the depths of the universe than it would have on the ground.

In astronomy, seeing beyond is equivalent to being able to observe phenomena that occurred in earlier cosmic periods – as light and other types of radiation have traveled longer to reach us.

Distant object: Astronomers believe they have identified the ancestor of a supermassive black hole (depicted in an artist's impression), which was born relatively soon after the Big Bang

Distant object: Astronomers believe they have identified the ancestor of a supermassive black hole (depicted in an artist’s impression), which was born relatively soon after the Big Bang

WHAT IS A QUASAR?

‘Quasar’ is short for quasi-stellar radio source and describes bright centers of galaxies.

All galaxies have a supermassive black hole at their core.

When the influx of gas and dust into this black hole reaches a certain level, the event can create a ‘quasar’ – an extremely bright region as the material swirls around the black hole.

They are typically 3,260 light-years across.

These regions emit enormous amounts of electromagnetic radiation in their jets and can be a trillion times brighter than the sun.

But they only last on average 10 to 100 million years, making them relatively difficult to see in galaxies several billion years old.

The fast-spinning disk spews out particles that move outwards at speeds approaching that of light.

These energetic ‘motors’ are bright transmitters of light and radio waves.

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The research was conducted by an international team of experts led by astrophysicists from the Niels Bohr Institute, the University of Copenhagen and the Technical University of Denmark.

“The discovered object links two rare populations of celestial bodies, dusty starbursts and luminous quasars, thereby opening up a new avenue for understanding the rapid growth of supermassive black holes in the early Universe,” said Seiji Fujimoto of the University of Copenhagen.

The newly found object — dubbed GNz7q by the team — was born 750 million years after the Big Bang, which is widely regarded as the beginning of the universe as we know it.

Since the Big Bang happened about 13.8 billion years ago, GNz7q has its origins in an era known as ‘Cosmic Dawn’.

The discovery is linked to a specific type of quasars, which are extremely luminous objects.

Images from Hubble and other advanced telescopes have revealed that quasars exist at the heart of galaxies.

The host galaxy for GNz7q is an intense star-forming galaxy, forming stars at a speed 1,600 times faster than our own galaxy, the Milky Way.

The stars, in turn, create and heat cosmic dust, causing it to glow in the infrared to such an extent that the host of GNz7q sheds more light in dust emission than any other known object during this period of the Cosmic Dawn.

In recent years, it has been found that luminous quasars are powered by supermassive black holes, with masses ranging from millions to tens of billions of solar masses, surrounded by enormous amounts of gas.

If the gas falls to the black hole, it will heat up due to friction, causing the enormous light effect.

“Understanding how supermassive black holes form and grow in the early Universe has become a great mystery,” Associate Professor Gabriel Brammer of the University of Copenhagen.

Theorists have predicted that these black holes undergo an early phase of rapid growth: a dust-red compact object emerges from a heavily dust-obscured starburst galaxy and then merges into an unobscured luminous compact object through the surrounding gas and to expel dust.’

He added: ‘Although luminous quasars had been found in the earliest epochs of the universe, the transitional phase of rapid growth of both the black hole and its star-bursting host had not been found in comparable epochs.

“In addition, the observed properties are in excellent agreement with the theoretical simulations and suggest that GNz7q is the first example of the transitional, fast-growth phase of black holes in the dusty stars, an ancestor of the later supermassive black hole.”

The newly found object — dubbed GNz7q by the researchers who discovered it — is pictured here in the center of the Hubble GOODS-North field image.

The newly found object — dubbed GNz7q by the researchers who discovered it — is pictured here in the center of the Hubble GOODS-North field image.

Both Fujimoto and Brammer are part of the Cosmic Dawn Center (DAWN), a collaboration between the Niels Bohr Institute and DTU Space.

Curiously, GNz7q was found at the center of an intensely studied celestial field known as the Hubble GOODS North field.

“This shows how great discoveries can often remain hidden from view,” says Brammer.

The team now hopes to search for similar objects using NASA’s newly launched James Webb Space Telescope.

“The James Webb telescope makes it possible to fully characterize these objects and examine their evolution and underlying physics in much more detail,” Fujimoto said.

“Once Webb is up and running, he will have the power to decisively determine how common these fast-growing black holes really are.”

The research is published in the journal Nature.

BLACK HOLES HAVE A GRAVITY SO STRONG EVEN LIGHT CAN’T ESCAPE

Black holes are so dense and their gravitational pull so strong that no form of radiation can escape them – not even light.

They act as intense sources of gravity that suck up dust and gas around them. Their intense gravitational pull is believed to be what stars in galaxies revolve around.

How they are formed is still poorly understood. Astronomers think they could form when a large cloud of gas up to 100,000 times larger than the Sun collapses into a black hole.

Many of these black hole seeds then coalesce to form much larger supermassive black holes, found at the center of every known massive galaxy.

Alternatively, a supermassive black hole seed could originate from a giant star, about 100 times the mass of the sun, which eventually forms into a black hole after it runs out of fuel and collapses.

When these giant stars die, they also go “supernova,” a massive explosion that expels matter from the star’s outer layers into deep space.

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