Rapid radio bursts have been detected in a nearby galaxy

What is relevant about this explosion of radiation is not so much the detection itself, but its origin. Why?

The cosmos may seem like a cold, terrifying void; but, in reality, an incessant traffic of radiation flows in space from the celestial bodies that emit it: stars like our Sun, neutron stars, or even entire galaxies…

There is a particular type of radiation called rapid radio bursts, or fast radio bursts (FRB). Scientists have been hunting these bursts for a decade, but it is an arduous task, given that their presence lasts only a few milliseconds on the detection instruments; they could come from anywhere in the universe. Despite having detected hundreds of such bursts, scientists have only been able to determine the origin of about two of them. The first, in 2017; and the second, now.

The new detection, moreover, is most unusual; not only because the FRB are very elusive, but because their origin is a galaxy very similar to ours, the Milky Way.

The discovery was made using eight telescopes from the UK to China, and was published last January 6 in the magazine Nature.

But this detection generates more questions than answers.

According to the authors of the research, the relevance of this explosion of radiation is not so much the detection itself, but its origin. What are you talking about?

"What is very interesting about these FRB is that they have originated in the arm of a spiral galaxy similar to the Milky Way, and it is the closest blast to Earth we have located so far," scientists say.

How was this detected?

The technique used is known as very long baseline interferometry, through the CHIME telescope, which achieved a resolution high enough to locate the explosion in a region approximately seven light-years across, a feat comparable to that of an individual on Earth capable of distinguishing a person on the Moon.

500 million light-years from Earth, the source of this explosion, called FRB 180916 is seven times closer than the only other repeat explosion that has been located, and more than 10 times closer than any of the few repetitive explosions that scientists have managed to identify.

The unique proximity and repetition of this FRB could allow observation at other wavelengths and the potential for a more detailed study to understand the nature of this type of burst.

What could be producing these bursts?

As stated previously, stellar objects produce radiation. However, the artifacts created by humans, too. Does this mean that some kind of artificial object created by some unknown civilization is what’s causing these bursts? What would this place be very similar and close to our own galaxy?

The first FRB detection was discovered in a small "dwarf" galaxy containing metals and stars already formed. But these Frbs break the uniqueness of the former mold, which means that we have to consider perhaps multiple origins or a wider range of theories to understand what creates the Frbs. But we cannot yet make such an adventurous conclusion about the origin of this radiation.

Reference: B. Marcote et al. A repeating fast radio burst source localized to a nearby spiral galaxy, Nature (2020). DOI: 10.1038/s41586-019-1866-z

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