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.
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.
"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."
