Astronomers in Australia have created a 'unique view' of the Milky Way by taking information from a radio telescope and producing an image of what our galaxy would look like if humans could see radio waves.
The image from the Murchison Widefield Array telescope shows low-frequency radio emissions from the centre of the galaxy in yellow and gold, with flecks of blue and green.
'Our images are looking directly at the middle of the Milky Way, towards a region astronomers call the Galactic Centre', says Astrophysicist Dr Natasha Hurley-Walker.
The team from Curtin University used the massive image to discover the remnants of 27 massive stars that exploded in supernovae, one of which happened 9,000 year ago and would have been visible in the Earth sky.
These giant star explosions visible in the image would have been eight or more times more massive than the sun before their dramatic destruction.
Dr Hurley-Walker says younger supernova remnants are easier to spot than the older ones seen in the image and 295 are already known.
She said one of the newly-discovered supernova remnants lies in an empty region of space, far out of the plane of our galaxy.
'It's the remains of a star that died less than 9,000 years ago, meaning the explosion could have been visible to Indigenous people across Australia at that time.'
Anthropologists from Australia hope to be able to examine the traditional records of the aboriginal people to see if there is any cultural memory of these events.
Some Aboriginal traditions do describe bright new stars appearing in the sky, but we don't know of any definitive traditions that describe this particular event', said Duane Hamacher from the University of Melbourne, an expert in cultural astronomy.
'Now that we know when and where this supernova appeared in the sky, we can collaborate with Indigenous elders to see if any of their traditions describe this cosmic event. If any exist, it would be extremely exciting,' he said.
The images are taking using the GaLactic and Extragalactic All-sky MWA survey - or GLEAM for short.
The system has a resolution of two arcminutes (about the same as the human eye) and maps the sky using radio waves at frequencies between 72 and 231 MHz (FM radio is near 100 MHz).
'It's the power of this wide frequency range that makes it possible for us to disentangle different overlapping objects as we look toward the complexity of the Galactic Centre,' Dr Hurley-Walker said.
'Essentially, different objects have different radio colours, so we can use them to work out what kind of physics is at play.'
There were several 'surprises' found within the data, according to Dr Hurley-Walker and her team from Australia.
Two of the supernova remnants discovered in the image were 'orphans' - that means they were found in a region of sky where there are no massive stars.
Other supernova remnants discovered in the research are very old.
'This is really exciting for us, because it's hard to find supernova remnants in this phase of life--they allow us to look further back in time in the Milky Way', she said.
The team hope to be able to discover much more in future, as the next generation of radio telescopes come online.
The Square Kilometre Array, which is due to be built in Australia and South Africa from 2021 will be much more sensitive than the one used to create this image.
"The low-frequency part of the Square Kilometre Array will be thousands of times more sensitive and have much better resolution.
'It should find the thousands of supernova remnants that formed in the last 100,000 years, even on the other side of the Milky Way."
The research has been published by the International Centre for Radio Astronomy Research.
This article has been adapted from its original source.
