A huge amount of new fast radio bursts (FRBs) can help astronomers finally get a grip on these mysterious and powerful explosions from space.
A new study reports the detection of 19 formerly undiscovered FRBs, including the closest closest to the earth and the brightest ever seen. The results significantly increase the total number of impressions; only three dozen FRBs were previously known, with the first detection in 2007.
FRBs are short (milliseconds long) but intense emissions of radio light, which in almost a century can pack as much energy as our own sun produces. Their source is the subject of much debate and debate. For example, some researchers have suggested that FRBs can be generated by advanced extraterrestrial civilizations, although most astronomers prefer natural explanations, such as fast rotating neutron stars. [13 Ways to Hunt Intelligent Aliens]
The new study will be led by Ryan Shannon from the Swinburne University of Technology in Australia. Since early 2017, he and his team have been searching for FRBs using the Australian Square Kilometer Array Pathfinder (ASKAP), a network of 36 radio stations in Western Australia.
The systematic hunt has already yielded 20 FRBs, the researchers report in the new newspaper, published today (October 10) online in the journal Nature. (One of the eruptions they saw was mentioned earlier in another article, so the count of new FRBs is technically 19.)
The success rate of the team can be reduced to two factors, said co-author Keith Bannister of the Commonwealth Scientific and Industrial Research Organization (CSIRO), the national science agency of Australia, which designed and developed ASKAP.
"The telescope has an amazing field of view of 30 square degrees, 100 times larger than the full moon," Bannister said in a statement.
"And by using the dish antennae of the telescope in a radical way, with each pointing to a different part of the sky, we saw 240 square degrees at once – about 1000 times the area of the full moon," he added. "ASKAP is amazingly good for this work."
The team's analyzes show "that fast radio bursts are coming from the other side of the universe instead of from our own galactic neighborhood," Shannon added in the same statement.
The researchers have brought the nearest FRB to earth – an event known as FRB 171020, which came from about 425 million light-years from our planet. That is about twice as close as the previous record holder, Shannon told Space.com.
And the ASKAP survey has discovered the most powerful FRB known – again, by a factor of two, said Shannon, who is also affiliated with the Center of Excellence of the Australian Research Council for Gravitational Wave Discovery (OzGrav).
None of the newly detected FRBs appeared to flicker more than once during the research period, although the team repeatedly noticed FRB repeat fields and spent more than 12,000 hours following FRB finds, Shannon said.
Indeed, to date, only one "repeater" has been confirmed – a source called FRB 121102, which has fired several times since its discovery in 2012, including a barrage of at least 93 in the course of a single day in August 2017 .
The strange example of FRB 121102 and the new results raise an important question, Shannon said: "Are there two classes of FRB sources? The differences between the repeater and the others are too difficult to ignore."
There is another important implication of the new study, he added. The ASKAP FRBs are brighter than previous detections and they have a lower "spread". Dispersion refers to the spreading or smearing of the various wavelengths that make up a burst – in fact, how much these different wavelengths are delayed by material that intervenes from the FRB source to the earth.
"The fact that there is a relationship between clarity and dispersion tells us that the material that produces the dispersion is outside of the galaxies, in the weak weak gas in the intergalactic medium," Shannon told Space.com via e-mail. "This means that we can use FRBs to study this material, which is almost impossible to observe with other techniques (eg optical X-ray observations)."
In the future, Shannon and his colleagues want to determine the location of the FRBs. They should be able to bind every outburst to their home galaxy, the researchers said.
As the name implies, ASKAP is a scout for the Square Kilometer Array (SKA), a huge network of radio dishes in Australia and South Africa that will take shape in the coming years. The SKA can ultimately find many more FRBs, said the members of the study team.
Mike Wall's book on the search for extraterrestrial life, "Outside, "will be published on November 13 by Grand Central Publishing. Follow him on Twitter @michaeldwall. follow us @Spacedotcom or Facebook. Originally published on Space.com.