A Fast Radio Burst, or FRB, is a transient radio pulse originating from an unknown high-energy astrophysical phenomenon. Lasting milliseconds, The majority of FRBs are one offs, occurring quickly only to never reappear again, however several repeating FRBS have been detected.
Extremely energetic at its source, these bursts experience a drop of signal strength as they travel through the Cosmos. The origin of these strange occurrences remains uncertain, however the general consensus among astronomers suggests that FRBs emit from extragalactic sources. A fairly recent discovery, the first FRB was detected in 2007 by Duncan Lorimer and David Narkevic, during an examination of archival survey data from the Parkes Radio Telescope in New South Wales, Australia. While searching for signals within the Magellanic Clouds, they happened upon a rather brilliant pulse that occurred on July 24, 2001 lasting no more than 5 milliseconds. The FRB gained the designation Lorimer Burst FRB 010724, and is commonly referred to as the Lorimer Burst. For nearly a decade, most FRBS were detected in this manner, though the Lorimer Burst remained unique for some time due to its intensity. In 2013, four similar “Lorimer Bursts” were detected, and henceforth established the term Fast Radio Burst
Researchers found these four bursts as a part of the 2010 High Time Resolution Universe Surveys conducted at Parkes. Curiously, the brightest of these bursts displayed a classical dispersion sweep, demonstrating scatter-broadening with power law dependencies, an indication of what a radio emission from an extra-terrestrial source might look like.
Of the less than 100 confirmed FRBs, until recently, only three are known repeaters. Unlike their singular counterparts, repeating FRBs offer researchers an opportunity to examine these mysterious occurrences. The first notable repeating FRB was discovered in archival data from 2012. Designated 2012 FRB 121102, astronomers revealed that the signal originated from a dwarf galaxy 3 billion light-years away from the Milky Way. In 18 follow up observations, scientists focused on the length of the bursts and two primary qualities: the dispersion and polarization of the radio bursts.The wave’s dispersion relates to the frequency of one wave separated from another while the polarization determines the direction where the bursts travel. Dispersion offers hints to the environment surrounding the source of the FRB and the polarization allows researchers to learn more about the source.
All observations had similar polarization revealing that Whatever created these bursts has a constant orientation relative to the Earth. Meanwhile, the dispersion revealed that the Source of the burst is surrounded by electrons and shrouded within a violent magnetic field, all the key indicators of a presence of a black hole.
One particular burst lasted approx. 30 microseconds, implying that the source was about 10 km across, curiously the same size about of a neutron star.
This theory suggests that the source of these Fast Radio Bursts is a byproduct of a neutron star colliding with a black hole. It is unknown how or why a neutron star would create a FRB and If this is indeed a collision between celestial objects, what occurs beyond the event horizon that causes these high powered radio bursts? Until recently, only three repeating bursts were ever detected since the initial discovery of the Lorimer Burst in 2007. That changed in August 2019, when astronomers detected eight repeating FRB signals.
A team of astronomers from McGill University in Montreal, Canada identified the FRBs using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. Follow up observations aim to map slash triangulate their locations. Some fun factoids lol that they drew from CHIME is that the disperision is atypical for previous FRBs. Evidence suggests that these 8 have larger burst widths than non repeating burst, but this all remains to be seen yada yada. If you are reading this transcript, I love you 🙂
Though follow ups are basically necessary, scientists remark on the significance of this discovery for the progress of understanding the nature of these strange space lazers. 🙂
What are Fast Radio Bursts? How are they created and where do they come from? The answer remains inconclusive.