Scientists detect eight mysterious repeating deep space signals

Posted Aug 16, 2019 by Tim Sandle
An unprecedented eight repeating radio signals, or fast radio bursts, have been detected emanating from deep space. Astronomers are edging closer to unraveling the mystery.
Spiral Galaxy NGC 2841
This image from NASA's Spitzer Space Telescope shows the spiral galaxy NGC 2841, located about 46 million light-years from Earth in the constellation Ursa Major.
Early in 2019, one of the mysterious signals termed fast radio burst (FRB) 121102 was recorded and it was noted that the burst flashed repeatedly. A short while later astronomers recorded a second repeating one radio burst, which they coded FRB 180814. In all eight repeating radio bursts were recorded, each detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope, located at the Dominion Radio Astrophysical Observatory in British Columbia.
In all the total number of known repeating fast radio bursts stands at ten. The increased number is helping scientists to work out exactly what these signals are. A fast radio burst is a transient radio pulse of length, which ranges from a fraction of a millisecond to a few milliseconds. While the time is short, the energy release is massive - these bursts can discharge more energy than 500 million Suns. These spikes of radio data are caused by a high-energy astrophysical process which not yet understood.
Up until now these bursts were detected once and then they seem to disappear, which made tracking them near impossible. The fact these new radio bursts are repeating offers new opportunities to help pinpoint the location. The fact the bursts are reoccurring and there are ten of these identified perhaps indicates that fast radio bursts are not as uncommon as previously thought.
According to one of the scientists involved with the discovery, Ziggy Pleunis: "There is definitely a difference between the sources, with some being more prolific than others."
He adds, in conversation with Science Alert: "We already knew from FRB 121102 that the bursts can be very clustered: sometimes the source doesn't burst for hours and hours and then suddenly you get multiple bursts in a short amount of time."
The results could also suggest that all fast radio bursts are actually capable of sending repeating signals; it is just that some are less active and others are more active, in relation to our current technological limits of detection. However, it also stands that the individual bursts of those radio bursts which repeat tend to last for a longer time period than those that have, so far, been detected as single events. There are also differences in terms of the magnitude of the frequencies.
The researchers are moving closer to being able to match the eight new repeaters to known galaxies, by being able to gather more data and use this to assess the signal origin. This will not reveal the types of objects producing the radio bursts, however. This will require more data and analysis. One theory is that the bursts are the result of a collision between very dense objects like merging black holes or neutron stars.
The research will be published in The Astrophysical Journal and it is titled "CHIME/FRB Detection of Eight New Repeating Fast Radio Burst Sources".