Fast Radio Bursts, powerful signals coming from outer space, have been found to originate in galaxies similar to our own, the Milky Way Galaxy.
Signals come from distant galaxies in outer space; we can’t understand what or who is causing them. These signals encompass enormous amounts of energy. One signal is believed to pack as much energy as our Sun emits during a human lifetime. But the signals do not last long. They are quick. Fast, lasting only a few milliseconds. Astronomers call them Fast Radio Bursts, and FRBs are one of the most enigmatic problems among astronomers.
It could be artificial
Not only because they represent something we are not accustomed to but because artificial sources could very well cause them. The first FRB was spotted 13 years ago when scientists using Australia’s Park Radio Telescope noticed a strange single—a very bright but bride radio plus lasting a few milliseconds, coming from outer space. When FRBs were discovered, we didn’t know what we were looking at or how often fast radio bursts are emitted. It was first thought that they were entirely uncommon, but astronomers now believe several thousand FRBs occur over 24 hours over the entire sky. Of the hundreds of fast radio bursts found to date, the most famous is the FRB 121102.
It is the most famous and unusual one because it is the first fast radio burst that has burst a few hundred times since it was first spotted six years ago. Astronomers tried tracing the mystery signal to a specific region in space and succeeded: FRB 121102 comes from a small dwarf galaxy located a staggering 3 billion light-years away. Although hundreds of fast radio bursts have been detected across the sky, many enigmas surround them, the greatest of which is what causes them. Are FRBs created when distant stars collide? Are fast radio bursts the result of black hole mergers? Do supermassive black holes produce them? Or, is there a chance that FRBs are broadcasts from distant alien civilizations, trying their best to see whether someone is out there?
More questions than answers
While we can’t answer the above questions with our current data, studying FRBs can help us determine their origin. According to CSIRO astronomer Dr. Shivani Bhandari, FRBs are not caused by Black Holes. A paper published by Bhandari in the Astrophysical Journal Letters suggests that several FRBs originated not from the center of galaxies but from regions located close to their edge. As far as we know, there are black holes at the center of each galaxy. So, unless there are black holes at the edges of certain galaxies, then FRBs are not caused by Black Holes. In the study, Bhandari and her colleagues discovered that certain FRBs were coming from galaxies’ very outskirts, eliminating the possibility that supermassive black holes cause them.
Specifically, Bhandari and her team found that four distinct FRBs—FRB 180924, FRB 181112, FRB 190102, and FRB 190608 originated far from the heart of their galaxies. They discovered this by looking at the sky using the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. Follow-up observations were made with several optical telescopes, including the famous Very Large Telescope in the Atacama desert, to confirm their discovery. Observations and studies of the fast radio burst revealed something the four FRBs had in common.
In galaxies, far, far away
However, located several billion light-years away, all seemed to originate from massive galaxies forming new stars at moderate rates, comparable to the very functioning of our Milky Way Galaxy. The study also revealed that it was very unlikely that fast radio bursts originated from the explosions of stars or cosmic strings. However, there are still chances that white dwarf star mergers or neutron stars could explain FRBs. The alien civilization equation is still a strong-standing theory.