Fast Radio Bursts (FRBs) are incredible emissions of energy lasting a fraction of a second that we detect with radio telescopes. They are also an enduring mystery as we still do not know their exact cause.
Fewer than 100 of these bursts have ever been recorded, and for the most part, they appear to only happen once and then never again. Two, however, have been observed repeating: FRB 121102 (announced in 2014) and FRB 180814 (announced in January 2019).
Up until last week, we knew the galaxy of origin of just one fast radio burst, the repeating FRB 121102, with astronomers announcing its location back in 2017. Then, last week it was announced that the origin of the first non-repeating burst, FRB 180924, was discovered. This week, scientists have announced the location of a second non-repeating FRB.
As reported in Nature, FRB 190523 was detected on May 23 by Caltech's Owens Valley Radio Observatory, and using the W. M. Keck Observatory in Hawaii, researchers were able to locate the source of this burst to a Milky Way-type galaxy 7.9 billion light-years away.
Last week's FRB 180924 was also located in an average galaxy, relatively closer at 3.6 billion light-years away. This is in stark contrast with the location of FRB 121102. We suspect that the repeating bursts come from a magnetar, a highly magnetic neutron star, in a very active dwarf galaxy. The recent findings suggest that FRBs can be produced in a variety of environments.
"This finding tells us that every galaxy, even a run-of-the-mill galaxy like our Milky Way, can generate an FRB," lead author Professor Vikram Ravi, from Caltech, said in a statement. "The theory that FRBs come from magnetars was developed in part because the earlier FRB 121102 came from an active star-forming environment, where young magnetars can be formed in the supernovae of massive stars. But the host galaxy of FRB 190523 is more mellow in comparison."
To finally understand how these dramatic and peculiar events occur, it is crucial to find out where they come from. This gives astronomers a chance to find possible hints of what their source is by pointing all our telescopes at these galaxies and catching the after-effects of the radio burst.
Astronomers estimate that 10,000 FRBs could be detectable from Earth on any single day. While it is not possible to constantly monitor the whole sky all of the time, upcoming radio projects such as the Square Kilometer Array and the Deep Synoptic Array are expected to make hundreds of new detections and localizations of FRBs every year.