Mysterious burst of radio waves traced to galaxy billions of light-years away

by Miriam Kramer

For the first time, a mysterious blast of energy known as a Fast Radio Burst (FRB) has been precisely traced to a distant galaxy, bringing scientists even closer to figuring out the origins of these odd cosmic flashes. On April 18, 2015, a telescope caught sight of the FRB, and mere hours later, other telescopes found its location, tracing the source of the burst to a galaxy about 6 billion light-years away, according to a new study published in the journal Nature this week.
This marks the first time the distance to an FRB has been measured.

FRBs send out as much energy in a fraction of a second as the sun puts out in 10,000 years, but they are exceedingly difficult to find. 

SEE ALSO: Mysterious cosmic radio burst spotted in real time from Australia

Plus, no one is sure exactly what creates them.

“Our discovery opens the way to working out what makes these bursts,” Simon Johnston, one of the team members who made the FRB discovery, said in a statement.

The authors of the Nature study suggest that the April FRB — which took six days to fade — may have been produced by the merger of two compact stars, which sent out the radio burst.
It's also possible that more than one kind of cataclysmic event in the universe can create an FRB. For instance, some models suggest that a supernova explosion or a pulsar — a rotating neutron star — pulse could create an FRB.
"I've been pretty skeptical of the 'compact object merger' hypothesis, but the authors' observations are just beautifully consistent with what you'd expect," astronomer Peter K.G. Williams, who is unaffiliated with the study, told Mashable via email.
"But I've also heard rumors about other results that other teams that are working on that are totally inconsistent with this hypothesis, so the theorists still have a lot of work left to do! It's an exciting time."

Astronomer Duncan Lorimer, the author of a News and Views companion piece in Nature, gets a little more specific and suggests that this FRB may have been produced when two neutron stars merged. 

That possibility could present even more exciting options for follow up studies during future events. 

"Such a system would emit a large fraction of its energy in the form of gravitational waves, which are produced by accelerating bodies, according to Einstein’s general theory of relativity," Lorimer wrote.

If FRBs can be produced by neutron star combinations, and if gravitational waves — ripples in the fabric of space-time — can be detected with them, it could have serious implications for the future of astronomy.

A zoom-in of an elliptical galaxy showing the FRB pulse detection.

"This is getting a bit ahead of ourselves, but a simultaneous detection of an FRB and a gravitational wave event would be — this is a technical term — totally bananas," Williams said.

Astronomers recently detected gravitational waves for the first time, opening up a new door into the universe. Now, scientists can learn more about the most cataclysmic crashes between massive objects like black holes. 

If FRBs are also associated with these extreme collisions, scientists will have another data point that can be used in investigating these major and mysterious events. 

All the stuff in the cosmos

The FRB observed in April is also being used as a cosmic scale for the universe. 

Because scientists know the distance to the FRB galaxy, they were able to measure the material between the Milky Way and the elliptical galaxy that played host to the burst.

"By also having a distance we can now measure how dense the material is between the point of origin and Earth, and compare that with the current model of the distribution of matter in the universe," Johnston said. “Essentially this lets us weigh the universe, or at least the normal matter it contains."

The results of the study appear to confirm the model currently in use: The universe is about 70 percent dark energy, 5 percent regular matter and 25 percent dark matter. 

Until now, scientists weren't able to find half of the regular matter, so researchers referred to it as "missing," but the new measurement seems to find that matter, according to the study's authors.

"It’s the first time a fast radio burst has been used to conduct a cosmological measurement," Evan Keane, co-author of the new study, said in the statement.
At the moment scientists have only observed 17 FRBs, and most of them have been found by going back through old data; however, the future of this research is looking bright.

"There are good reasons to think that our understanding of FRBs will increase dramatically in the near future," Lorimer said. "New telescopes,including the Canadian HydrogenIntensity Mapping Experiment and the Five hundred-meter Aperture Spherical Telescope in China, should discover many FRBs."