Two years ago, the Chinese giant telescope FAST received more than 1,650 mysterious radio flashes from a single source, more than all of the Fast Radio bursts previously received combined. This by far the largest collection of FRB could help solve the riddle of the origin of the still unexplained signals, the discoverers believe.
There are currently two preferred theories to explain the phenomenon and for one of them the discovery presented is a major challenge. They come from a source from which several dozen signals had already been received. Their origin had been narrowed down to a dwarf galaxy some three billion light years away.
Discovered with a giant telescope in China
The first Fast Radio Bursts were discovered in 2007, since then there has been much speculation about their origin – even about whether they are possible traces of extraterrestrial spaceships. With the short but extremely violent bursts of radiation, more energy is emitted within milliseconds than the sun generates in a year. That is why they can still be detected from extreme distances. Most FRB were registered only once, but recently there have also been more and more observations of repetitive FRB. Periodic sources were also registered, such as a multitude of signals from one source such as now featured in the journal Nature There have not yet been any observations.
In total, the five-hundred-meter Aperture Spherical Telescope (FAST) in China recorded exactly 1,652 signals from the source called FRB 121102 between the end of August and the end of October 2019. In some cases, 122 signals were measured per hour. Even before these new record values, the source was exceptional, for example in 2018 an AI had detected 72 FRB in signals from there. The FAST has only been in operation since 2016 and is the largest radio telescope in the world with a fully filled bowl. Since the destruction of the legendary Arecibo telescope, it is unique in the world. In old Arecibo telescope data, FRB 121102 was discovered in 2016. Since then, the source has played a key role in research into the FRB.
Like the one involved in the analysis of FRB 121102 Astrophysicist Bing Zhang of the University of Nevada now explains, the most widespread explanations for fast radio bursts assume that they come from so-called magnetars. These are extremely dense neutron stars with the strongest magnetic fields in the universe. Where exactly the Fast Radio Bursts originate there are two possible explanations. They could either come from their magnetic field or they could be ignited by immensely accelerated particles outside the so-called magnetic sphere. The signals that are now publicly presented are too numerous and too energetic for the latter.