The Dish detects strange deep space blasts
Mystery blasts A series of mysterious radio bursts, each lasting just a few milliseconds, have been detected coming from far beyond our galaxy.
The brightness of these explosive pulses, known as FRBs or fast radio bursts, suggests they come from billions of light years away, when the universe was just a fraction of its current age, report astronomers in the journal Science.
The discovery confirms the authenticity of a similar signal called the Lorimer burst, detected in 2007, says the paper's lead author PhD student Dan Thornton of the CSIRO and the University of Manchester.
That event was traced to the edge of a nearby dwarf galaxy called the Small Magellanic Cloud.
"We have spent the last four years searching for more of these," says Thornton.
The latest bursts, detected using Australia's 64 metre CSIRO Parkes Radio Telescope, are the first confirmed to have come from so far back in cosmological time.
While the exact cause of the bursts remains a mystery, they may be coming from unusual neutron stars called magnetars, says study co-author Matthew Bailes of Melbourne's Swinburne University.
"These are the most magnetic stars in the universe, and every now and then they have very large explosions on them, which may be a good candidate for the origin of these things," says Bailes.
"They can give off as much energy as the Sun does for 300,000 years, in just a millisecond."
The researchers found the bursts matched a predictable set of characteristics expected from an extragalactic pulse.
One of the most exciting applications from the discovery could be the bursts ability to reveal new details about the vast regions of intergalactic space the signals have traversed.
Bailes says the bursts are an amazingly powerful cosmological probe for weighing the normal matter in the universe.
"It's really a dream come true, because it gives our technique for finding pulsars, a whole new use," says Bailes.
"Every time the radio waves go past an electron, the electron's presence gets encoded in the burst of photons.
"We can use this to count how many electrons there are between us and half way across the universe, which is incredibly exciting because almost all of the normal atoms are actually not in galaxies, they're just sitting around in the intergalactic medium."
The biggest problem however, will be establishing the source of the bursts.
"At the moment we can't locate exactly which galaxy it comes from," says Bailes.
"So we're going to have to come up with a way that we can get much better positions for the bursts."
The authors have set up a real time detector at the Parkes dish, which is finding a burst every 10 days.
In the future, other telescopes such as the Square Kilometre Array telescope could help pinpoint these bursts further, says Bailes.
"The Square Kilometre array will have such an extended array of telescopes all looking at the same spot at the same time, that they'll almost instantly get the location of these things," says Bailes.
The Molonglo Observatory Synthesis Telescope near Canberra is another option.
"It has an almost perfect combination of collecting area and field of view to do surveys," says Bailes.