Strange and intense blasts of radio energy were monitored within our own galaxy, say astronomers in a new study published in the journal Nature.
Mysterious radio signals detected inside our own galaxy, say scientists
Specifically, the detected signals are fast radio bursts (FRBs) — which last only a small fraction of a second but can possess more power than the sun itself. Despite the intensity of FRBs, their causal origin remains largely unknown, reports The Independent.
However, in the new study, astronomers observed a fast radio burst in our own Milky Way galaxy — for the first time. This is closer than any FRB previously detected, and might help astronomers understand from where and how they come to exist.
Scientists have long struggled to uncover the origin of these intense blasts because they're brief, unpredictable, and come from far away. But the consensus is they are formed within some of the most extreme conditions possible in our universe — with potential explanations ranging from dying stars to alien technology.
Two telescopes confirm several X-ray, gamma-ray bursts in our galaxy
The radio energy bursts seem to have come from a magnetar — which is a star with an extremely powerful magnetic field, said the scientists who observed the new FRBs. They confirmed the blast would appear like other, more distant FRBs if it were monitored from a viewpoint outside of our galaxy — which means some of the other blasts might come into existence via other similar objects, way out in deep space.
"There's this great mystery as to what would produce these great outbursts of energy, which until now we've seen coming from halfway across the universe," said Assistant Professor of Physics Kiyoshi Masui of MIT — who led the science team's analysis of the FRB's brightness. "This is the first time we've been able to tie one of these exotic fast radio bursts to a single astrophysical object."
The new FRBs were first detected on April 27, when researchers operating two space telescopes picked up several gamma-ray and X-ray emissions stemming from a magnetar on the other side of the galaxy. The very next day, researchers used two telescopes in North America to monitor the same patch of sky — and detected the blast later known as FRB 200428.
Narrowing patch of observed sky helps form links between radio energy and other phenomena
In addition to being the first FRB from the Milky Way and the first to relate to a magnetar, this is the first blast to exhibit emissions other than radio waves, The Independent reports.
The research was made possible with data gathered from telescopes around the world, via an international team of scientists making observations with equipment in the U.S., China, Canada, and outer space.
FRBs were initially discovered in the year 2007, and prompted an immediate cacophony of speculation regarding what might cause these intense blasts of energy. Magnetars have become the most likely candidate since then, given theoretical work suggesting their magnetic fields might work like engines producing the powerful cosmic blasts.
To test this, astronomers have tried to narrow down the origin of FRBs to sectors of the sky as small as possible. Theoretically, this should let scientists associate the blasts with known objects in space and seek out hidden associations between radio energy and other astronomical phenomena.
Even if magnetar confirmed as FRB origin, mysteries live on
This latest work is significant because it is the first to establish a link between FRBs and magnetars. If nothing else, it's a welcome break in the hunt for the origin of at least some FRBs.
"We calculated that such an intense burst coming from another galaxy would be indistinguishable from some fast radio bursts, so this really gives weight to the theory suggesting that magnetars could be behind at least some FRBs," said Pragya Chawla, one of the study's co-authors and a senior doctoral student in McGill's physics department.
However, the latest findings might not explain all known FRBs "given the large gaps in energetics and activity between the brightest and most active FRB sources and what is observed for magnetars, perhaps younger, more energetic and active magnetars are needed to explain all FRB observations," said Paul Scholz of the Dunlap Institute of Astronomy and Astrophysics, at the University of Toronto.
If or when the FRB is proven to have a magnetar as origin, astronomers will still face numerous mysteries. They'll look for the mechanism magnetars use to power an FRB, and seek out instances of this to comprehend how these bright, unusual bursts of maddening energy and X-ray emissions simultaneously, from within our galaxy.