Home / Science / Astronomers have discovered 8 new repeating signals from deep space

Astronomers have discovered 8 new repeating signals from deep space

One of the greatest mysteries out there in the universe is closer answers. An astonishing eight new repeating radio signals known as fast radio bursts (FRB) have been discovered that flare from deep space.

In early 2019, only one of these mysterious signals, FRB 121102, was known to blink repeatedly. In January, researchers reported a second repeat (FRB 180814).

This new paper – available on the arXiv suppression server and accepted in The Astrophysical Journal Letters – describes eight new repetitive signals discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope.

This brings the known sum of repeated FRBs to 10. This means that we are starting to build a statistical database of repeaters, which can help astronomers find out what these signals actually are

Rapid radio deficiencies are really confusing. They are detected as nails in radio data, lasting only a few milliseconds. But during that time, they can drain more energy than the 500 million sun.

Most FRBs are only discovered once and cannot be predicted, so tracing them back to their source is really tricky (although it was shown earlier this year for the first time, not impossible).

That's why repeaters are so important. And the news that they are not as rare as we thought means that it may be possible to trace more back to their source galaxies and determine what kind of environments they come from.

We can also start to look for similarities and differences between repeating FRB.

"There is definitely a difference between the sources, with some being more productive than others," physicist Ziggy Pleunis of McGill University told ScienceAlert.

"We already knew from FRB 1

21102 that the bursts can be very clustered: sometimes the source does not burst for hours and hours and suddenly you get several bursts in a short time. We have seen the same for FRB 180916. J0158 + 65, for which we reports ten bursts in this paper. "

On the other side of the scale, six of the FRBs reported in the newspaper reported only once, and the longest interval between signals was over 20 hours. The eighth (FRB 181119) was repeated twice after the first discovery and pinged a total of three times.

We do not yet know what this means, but it may indicate – as hypothesized in a paper last month by Harvard-Smithsonian astrophysicist Vikram Ravi – that all FRBs are actually repeaters, but some are much more active than others.

"Just like some volcanoes are more active than others, and you might think that a volcano is dormant because it has not erupted for a long time," Pleunis noted.

But there are similarities between FRB as well. The individual bursts from the repeater appear to be slightly longer than the bursts from individual FRBs. It's pretty interesting.

There is also frequency drift. The first two repeaters – FRB 121102 and FRB 180814 – showed a downward frequency drift, with each burst gradually decreasing. Think of a sad trombone sound effect.

Most of the eight new repeaters also showed this downward frequency drift. This can be a clue as to what produces the signals.

"I just think it's so amazing that nature produces something like that," Pleunis said. "In addition, I think there is a lot of important information in that structure that we just have to find out how to code and it's been very fun trying to find out what it is."

CHIME is optimized to monitor a very wide sky distance, over a lower frequency range than radio telescopes such as ASKAP or Parkes Observatory in Australia, which have also detected FRB.

To date, CHIME's strategy has proved remarkably effective at detection. In addition to these repeaters and repeaters announced in January, CHIME has discovered a number of one-off shortcomings as well. However, it is not optimized to trace these discoveries to a source.

This is where the broader scientific community comes in. Just today, another team of scientists, including Ravi, announced that they had made progress in locating the eight new repeaters into known galaxies, based solely on the direction the signals came from. [19659003] We can even roughly say how far away the bursts can have their origin based on how scattered the signal is – the higher these dimensions, the longer the distance.

This is actually where it gets exciting, because one of the signals, FRB 180916, has the lowest spread seen so far, indicating that it may be nearby.

"Even with the largest telescopes, if it's closer to you, you always get a better view than if it's a little further away," astronomer Keith Bannister of Australia's National Science Agency CSIRO, who was not involved in the research, told ScienceAlert .

"So the special action with low spread was extremely exciting, because there is a good chance that it will be nearby. And that means it will be easier to watch, when we really know exactly where it is in the sky . "

The polarization of the signals (how twisted the signal is) is also informative. If the signal is really turned up, it means it came from an extremely magnetic environment, which can be found around a black hole or neutron star. This was the signal from FRB 121102.

But the team was able to measure the polarization of one of the new signals, FRB 180916, and it was really low. This tells us that not all repeated FRBs come from extreme environments.

We don't know what this means yet. We do not know if there are several different classes of objects or events that produce these signals. We do not know if they all repeat, or why they repeat. But these results give us the alluring close to finally having some answers.

"I think (and I hope!) The paper will get other astronomers to point their telescopes at these newly discovered sources," Pleunis said.

"Then there is a lot of information here for model builders to work with. I think it will help them find out what gives repeating FRBs.

" I also think our results will affect the search strategy for other teams trying to discover repetitive FRB. "

The research has been accepted in The Astrophysical Journal and is available at arXiv.

Source link