Astronomers have identified the location of mysterious radio bursts found emitted from deep space, and say the signal is coming from a dwarf galaxy billions of light years away.

Key points: FRBs are explosions in space that emit huge amounts of energy

FRBs are explosions in space that emit huge amounts of energy The FRBS could help astronomers understand what is between galaxies

The FRBS could help astronomers understand what is between galaxies One theory is that they are coming from a magnetar — baby neutron star with an intense magnetic field

Scientists have called the discovery a game changer that could help them understand what was in the voids between galaxies.

Fast radio bursts (FRB) are highly energetic bursts of radio waves whose origins have been a mystery since they were first discovered in 2007 by researchers at Australia's Parkes Radio Telescope.

While an FRB's lifespan is short, they emit as much energy in one millisecond as the sun emits in 10,000 years.

FRBs were first discovered in 2007 by researchers at Australia's Parkes Radio Telescope. ( Supplied: CSIRO/David McClenaghan )

There are 18 known FRBs and all were discovered using single dish radio telescopes.

But those telescopes were unable to narrow down the objects location with enough precision to allow astronomers to locate where they were coming from in the universe.

That was until FRB 121102, discovered in November 2012 at the Arecibo Observatory in Puerto Rico.

Dr Shami Chatterjee from Cornell University said that particular FRB was repeating — the first one they had found to do so.

He said the repeat ruled out theories that the radio bursts could be coming from cataclysmic events, at least in the case of FRB 121102.

"Because we could say, 'look if the thing goes boom it can't come back and repeat'," he said.

"And it also tells us look if you go fishing at this spot, you might turn out to be lucky."

'It's quite a mind boggling concept'

They went fishing in the spot using the National Science Foundation's (NSF) multi-antenna radio telescope system — Karl G Jansky Very Large Array (VLA).

The VLA gave them a finer resolution of the sky and allowed them to pinpoint the source.

Dr Chatterjee said they found two things. One was a persistent source of weaker radio emission which he said they still did not understand.

But what they also found was a "faint little optical smudge", which turned out of be a dwarf galaxy.

They then took that optical smudge to the Gemini North telescope in Hawaii and took a spectrum, which though faint, had very clear spectral lines of hydrogen, oxygen and nitrogen.

"But at the wrong wavelength, the wavelengths are Doppler shifted because this dwarf galaxy is moving away from us," he said.

"And so from that we can infer how far away it is because the universe is expanding and the expansion gets faster as you get further away."

That was how they worked out that it was three billion light years away.

"That means that these fast radio bursts have been travelling for three billion years before we detect them on the ground — it's quite a mind boggling concept," Dr Chatterjee said.

The visible-light image that identified a faint dwarf galaxy at the location of the bursts. ( Supplied: Gemini Observatory/AURA/NSF/NRC )

Who or what is sending the signals?

Dr Chaterjee said there were a number of viable models that could be used to explain the potential ways the signals were being sent.

One was that they were coming from a black hole at the centre of the dwarf galaxy which was feeding on matter, and every time a jet from that hole blasted away a cloud of plasma a flash of radio waves was produced.

"I'm not a big fan of this, because it has some knobs that you can twiddle and it's not clear how it all works," he said.

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He said another model was that it was from a magnetar, which is a baby neutron star with an intense magnetic field, that could be producing giant pulses.

"Which are somehow being lensed by globs of plasma so that they are coming into focus just at the Earth, and every once in a while when they come into focus we can catch a pulse," he said.

Bursts can help 'tell us about the voids between galaxies'

Dr Chaterjee said they still did not know whether all FRBs were the same, or whether they were each different.

He said the discovery was a game changer because for the first time "we have no ambiguity in this host galaxy".

"Until now we had arguments saying ok it could be coming from here, it could be this far away, but now we know for the first time," he said.

"And where it worked out to be is possibly the most exciting version possible."

"These are cosmological, these are coming to us across the distant universe and they can really tell us about the voids between galaxies.

"We think space is empty in our galaxy, but the voids between galaxies are even emptier.

And so we are crossing billions of light years and there is next to nothing there and the only way we have right now is probing what's going on in there.

"These fast radio bursts could be a very useful tool to tell us what's between these galaxies."

The findings will be presented today at a meeting of the American Astronomical Society in the United States.