If you closely follow scientific discoveries about the universe, you’ll have read that across the sky as many as 10,000 celestial radio signals a day are emitting a bright pulse which lasts for only a few milliseconds.
And then, as far as scientists can tell, each pulse isn’t seen again.
You can’t see them with the naked eye, and scientists don’t know their origins or what they mean. And up until 2007, no one officially knew they existed.
Scientists at the Arecibo telescope in Puerto Rico have published findings recently that confirm the existence of these radio pulses that a West Virginia University undergraduate student first discovered.
David Narkevic, then a physics and political science student from Philippi, looked through data from the Parkes radio telescope in Australia and found a single pulse shorter than five milliseconds that didn’t seem to repeat.
“They are fairly easy to detect,” said Duncan Lorimer, astrophysics professor at WVU. “But what we can’t do easily is pinpoint their position.”
Lorimer remembers when Narkevic showed him the original burst. It was clearly from far beyond the Milky Way galaxy.
Until now, scientists only found other examples of the phenomenon at different locations in the sky fewer than 10 more times and only from data collected at Parkes. Lorimer said this led some researchers to suspect that the data could be reflecting the telescope’s activity and not the universe’s.
“It’s very significant,” he says of the most recent discovery, “because it’s the first example of one of these fast radio bursts found by a different telescope. We can be very, very confident now that it’s a celestial phenomenon. That’s the biggest take away result from this paper.”
With the recent news from Arecibo, the hunt is on to find out what’s really going on in each fraction of a degree of the sky where the bursts appear. And WVU researchers are very much a part of that.
The big question, Lorimer said, is whether the signals are coming from the neighborhood of our galaxy or whether they’re much further away in the cosmos.
“If you asked me to make a bet, I would say it’s more likely to be cosmological, but I can’t prove that at the moment,” he said.
That would tell us where they are. But what are they? They’re not pulsars, the spinning neutron stars that send beams of radio waves with more regularity than a military clock.
If they’re far away, Lorimer said, that probably puts them in the realm of the exotic. Stars colliding. The explosion of black holes—first proposed by Stephen Hawking in 1974.
He said this quest is reminiscent of the long road to discover the origin of gamma ray bursts, first noticed by military satellites in the 1960s. It took 30 years for scientists to prove that, yes, these bursts came from beyond our galaxy.
“So hopefully it won’t take us another 30 years to find the answer,” Lorimer said of these newly discovered bursts. “And it could actually be that these radio bursts are related to gamma ray bursts.
“I think within the next year or two we’ll know the answer to this basic question of whether they’re extragalactic or not.”
And it will be an exciting one or two years, he thinks.
WVU researchers are also at Arecibo and elsewhere gathering data in the field of radio astronomy, which in a matter of a few years has become a top specialty for the University.
Lorimer said right now the WVU Department of Physics and Astronomy is installing high-performance computing facilities at Arecibo to analyze data being collected for sightings of these bursts.
At the National Radio Astronomy Observatory in Green Bank, WVU researchers are involved in projects which are collecting data from the smaller telescopes on site as part of the search.
He and fellow professor Maura McLaughlin, among others at WVU, are well equipped to study these short radio bursts because they’re already looking for the radio waves that pulsars are sending in short, regular bursts.
In the last several years, they’ve co-led with the National Radio Astronomy Observatory a program that trains middle and high school students to search for radio waves, known as the Pulsar Search Collaboratory.
McLaughlin and Lorimer are also active participants in an international collaboration to use both the Arecibo and the Green Bank radio telescopes to detect using pulsar timing measurements, gravitational waves predicted by Einstein’s theory of general relativity.
Lorimer is available for media interviews, and can be reached at Duncan.Lorimer@mail.wvu.edu or 304-290-0417.