ASKAP telescope to rule radio-burst hunt
Gabby Russell
Communication Manager, Astronomy, Space and Supercomputing
Email gabby.russell(at)csiro.au
Keith Bannister
Principal Research Engineer
Email Keith.Bannister(at)csiro.au
Jean-Pierre Macquart
Email j.macquart(at)curtin.edu.au
A CSIRO telescope has found its first 'fast radio burst' from space after less than four days of searching.
[Music plays, and the screen shows a row of satellite dishes against a blue sky and bushland, with the overlay of the CSIRO logo spinning into place. Music and screen changes to show a blue background and the caption, "What is a fast radio burst?"]
[Man in a blue shirt appears, in front of two monitor screens, and the title Dr Keith Bannister, CSIRO Astronomer appears below]
Dr Bannister: A fast radio burst is very much like what it sounds. It's a very fast burst of radio waves. It comes from outer space, a long way away. And by fast, I mean really fast. So it starts and stops in about a thousandth of a second, [Keith clicks his fingers] so you click your fingers, and it's finished.
[Screen changes to blue, with the title, "What causes fast radio bursts?"]
[Dr Bannister reappears on the screen]
Dr Bannister: Fast radio bursts are a real mystery. We don't exactly understand where they come from, or what actually makes them. And there's a lot of open questions that we really don't have an answer for. There are probably more theories about what makes fast radio bursts, than there are actual detections of these things. So since 2007 we've only had 20, but there are probably 30 or 40 different theories on what makes them.
[Screen changes to blue, and the text "Our ASKAP telescope has just discovered its first radio burst." shows.]
[Dr Keith Bannister is shown again]
Dr Bannister: The most interesting thing about this burst is the fact that we found it with the Australian square kilometre ray path finder. So that is, it wasn't really obvious that we would be able to do this, as well as we ended up being able to do it. So this telescope is really a fantastic telescope. In fact it's probably the best telescope on the planet at the moment for finding these bursts. So whereas in the past it's taken ten years to find twenty bursts, once we're really going with this new instrument, we'll be able to find them much more quickly. One or two every week. And that will blow open the field. We'll be able to do much more detailed studies of these things, get better statistics, understand what, hopefully understand what they are, and where they're coming from. So the thing that's most interesting about this burst is the fact that it heralds a new era. Not only for the telescope, but for the whole field, where we'll be able to actually have lots more things to play with. That's probably the most important thing.
[Screen changes to blue, with the title, "Do you have a new nickname for ASKAP?"]
[Screen changes again to show Dr Bannister]
Dr Bannister: I liken it a little bit to the Saron of space, the all-seeing eye, because we see so much of the sky, in comparison with other telescopes, we really can catch these things really easily.
[Screen shows the blue background, and the title, "Why is this significant for research into fast radio bursts?"]
Dr Bannister: When you can find a whole bunch really quickly, which is what we can do now with the Australian square kilometre array pathfinder, we'll be able to get a nice uniform set that we can start to do some statistics with. So a classic thing we can do is measure how many really bright ones there are, versus how many faint ones, and that tells us whether the things that we're looking at come from fairly nearby, or really far away in the universe. Much further than we might even think.
[Screen changes to blue, and the CSIRO logo spins into place in the centre, with the words "Australia's innovation catalyst" beneath]
What is a fast radio burst?
The discovery came so quickly that the telescope, the Australian Square Kilometre Array Pathfinder (ASKAP) near Geraldton in Western Australia, looks set to become a world champion in this fiercely competitive area of astronomy.
The new fast radio burst finding was published today in The Astrophysical Journal Letters .
'Fast radio bursts' or FRBs are short, sharp spikes of radio waves lasting a few milliseconds.
They appear to come from powerful events billions of light-years away but their cause is still a mystery. The first was discovered in 2007 and only two dozen have been found since.
The discovery of the new burst, FRB170107, was made by CSIRO's Dr Keith Bannister and his colleagues from CSIRO, Curtin University and the International Centre for Radio Astronomy Research (ICRAR) while using just eight of the telescope's 36 dishes.
The discovery is the culmination of a decade of science and engineering development by CSIRO and Curtin University.
"We can expect to find one every two days when we use 12 dishes, our standard number at present," Dr Bannister said.
To make the most recent detection, the researchers used an unusual strategy.
"We turned the telescope into the Sauron of space – the all-seeing eye," Dr Bannister said, referring to the dark overlord in Tolkien's "Lord of the Rings".
Usually ASKAP's dishes all point at the one part of sky. But they can be made to point in slightly different directions, like the segments of a fly's eye.
This multiplies the amount of sky the telescope can see. Eight ASKAP dishes can see 240 square degrees at once – about a thousand times the area of the full Moon.
The new burst was found as part of a research project called CRAFT (Commensal Real-time ASKAP Fast Transients survey), which is led jointly by Dr Bannister and Dr Jean-Pierre Macquart from the Curtin University node of ICRAR.
Dr Macquart said the new burst was extremely bright and that finding it was "as easy as shooting fish in a barrel".
FRB170107 came from the edge of the constellation Leo. It appears to have travelled through space for six billion years before slamming into the WA telescope at the speed of light.
The burst's brightness and its apparent distance mean that the energy involved is enormous, making it extremely challenging to explain.
"We've made a hard problem even harder," said Dr Ryan Shannon (CSIRO, Curtin University and ICRAR), who analysed the burst's strength and position.
CSIRO Chief Executive Dr Larry Marshall said the FRB detection was a sign of the full potential of ASKAP.
"Radio astronomy has a long history of innovation in high-speed communications, and this unique capability is embedded into ASKAP – from the receiver to the signal processing – making it a uniquely powerful instrument for astronomy," Dr Marshall said.
In addition to the discovery of the new burst, Dr Bannister has a big reward – a happy family.
He'd been telling his three kids for months about his plans.
"Every day as I left for work they'd ask, 'Are you going to find a radio burst today, Daddy?'" he said.
And when it finally happened, "they were too excited for words".
"They just looked at me, smiled, and gave me a great big hug!"
CSIRO's Australian Square Kilometre Array Pathfinder at night. © Alex Cherney/terrastro.com
The signal of FRB 170107, found using CSIRO's ASKAP radio telescope in less than four days of looking. ©K. Bannister et. al
Dishes of CSIRO's Australian Square Kilometre Array Pathfinder ©Kim Steele
CSIRO's Dr Keith Bannister.
Dr Jean-Pierre Macquart of Curtin University. ©John Goldsmith
ASKAP has just discovered its first fast radio burst – why is this interesting?
What causes fast radio bursts?
Why is this significant for research into fast radio bursts?
The Sauron of space
The Detection of an Extremely Bright Fast Radio Burst in a Phased Array Feed Survey
Made up of 36 antennas working together as a single instrument, CSIRO's newest radio telescope – the Australian Square Kilometre Array Pathfinder, or ASKAP – will capture radio images of the sky in more detail and faster than ever before. It will allow astronomers to answer fundamental questions about our Universe, such as the nature of cosmic magnetism and the evolution and formation of galaxies.
ASKAP is located at the CSIRO-run Murchison Radio-astronomy Observatory in the Mid West region of Western Australia. The observatory is remarkably 'quiet': it is relatively free of human-generated radio signals that would otherwise interfere with weak radio waves from space.
We acknowledge the Wajarri Yamatji people as the Traditional Owners of the Murchison Radio-astronomy Observatory site.