(ORDO NEWS) — A newly discovered fast radio burst has unique properties that give astronomers important clues about what might be causing these mysterious astronomical phenomena themselves.
Fast radio bursts (FRBs) are extremely bright pulses of radio waves coming from distant galaxies. In one millisecond, they release as much energy as the Sun releases in many days.
Researchers at West Virginia University discovered the first DFS in 2007. Over the past 15 years, astronomers have discovered about 800 FRBs, and there are more of them every day.
When a telescope captures FRBs, one of the most important characteristics that researchers pay attention to is dispersion. Dispersion is essentially a measure of how much the FBW stretches when it reaches the Earth.
The plasma between stars and galaxies slows down all light waves, including radio waves, but low frequencies feel this effect more and slow down more than high frequencies.
FRBs contain a range of frequencies, so the higher frequency light in the burst hits Earth earlier than the lower frequency light, which causes dispersion.
This allows researchers to use variance to estimate how far from Earth the FRB originated. The more stretched the FRB, the more plasma the signal had to pass through, the farther the source must be.
Why is it important
The new BRV is called BRV190520. It was discovered using a spherical telescope with a five hundred meter aperture in China. What immediately caught my eye was that BRV190520 is one of 24 recurring BRVs and repeats much more often than others – 75 bursts over a six-month period in 2020.
The Very Large Array, a radio telescope in New Mexico, was then used to further study this FRB and successfully located its source, a dwarf galaxy located about 3 billion light-years from Earth. It was then that it became clear how unique and important this BRV is.
First, it was found that there is a constant, albeit much weaker, radio signal emitted from the same area as BRW190520. Of the more than 800 FRBs discovered to date, only one has such a permanent radio signal.
Secondly, since it was possible to accurately determine that the FRB comes from a dwarf galaxy, it was established how far this galaxy is from the Earth.
But this result made no sense. Surprisingly, the distance estimate that was made using the FRB variance was 30 billion light-years from Earth, which is 10 times greater than the actual 3 billion light-years to the galaxy.
Astronomers have only been able to determine the precise location, and therefore the distance from Earth, for 19 other FRB sources.
For the remaining approximately 800 known FRBs, we had to rely on dispersion alone to estimate their distance from Earth.
For the remaining 19 FRBs whose positions are known, the distances estimated from the variance are very similar to the actual distances to the source galaxies. But this new FFS shows that variance estimates can sometimes be wrong, and throws many assumptions out the window.
Astronomers in this new field still don’t know what exactly generates FRBs, so every new discovery or piece of information is important.
And the big mystery is why the variance of BRV190520 was so much larger than it should be. Was it connected to something near the BRV? Is it related to the source of constant radio signal? Is it related to the matter in the galaxy where this FRB is coming from? All these questions remain unanswered at the moment.
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