First discovered in 2007, FRB (or radio wave) emission is one of the most intriguing mysteries in modern astrophysics. They have been described as powerful electromagnetic signals that travel to Earth from deep space, over distances hundreds of millions of years to billions of light years.
Despite being extremely short, lasting at most a few milliseconds, the FRBs are extremely energetic, tens of thousands of times more powerful than the Sun, or equal to the total energy of the Sun continuously generated. during 80 years.
FRBs often travel to Earth from deep space, probably from galaxies hundreds of millions of millions of light years away, and can only be detected by radio telescopes.
Because FRBs exist for extremely short periods of time, they are usually only identified by data from radio observatories after signal reception. In 2007, scientists obtained the first FRB signal with the Parkes radio telescope in Australia. Since then, astronomers have collected nearly 100 FRB signals.
Because of observational methods and limited technology in humans, determining where FRBs come from and what makes them are still puzzling astronomers. Some scientists believe that FRBs are created from astrophysical phenomena in the universe, such as when two neutron stars collide, or emit black holes when they ‘devour’. matter from an ill-fated star. A small number of other scientists even hypothesize, this may be a form of communication of aliens.
Detect FRB on a 157-day cycle
Typically, FRB emissions reach the Earth at random and do not follow any rules. Most FRBs that have been detected only flare up once in 1 / 1000th of a second – faster than the blink of an eye – and are almost non-repeatable, making such events happen very difficult to predict and follow. track.
However, scientists have discovered the existence of two FRB emissions with an extremely abnormal signaling cycle.
Because of observational methods and limited technology in humans, determining where FRBs come from and what makes them is still a headache for astronomers.
Specifically, in January this year, the scientists discovered FRB emission codename 180916.J0158 + 65 with a 16-day operating cycle. It emits radio waves over a period of 4 days, stops for a period of 12 days, then repeats.
After FRB 180916, scientists recently continued to discover another FRB with another strange repetitive cycle. After following the Lovell Telescope in the UK for five years, scientists at the University of Manchester discovered that FRB, codenamed 121102, has a 157-day operating cycle. It emits radio waves for 90 days, then suddenly stays silent for 67 days. The signal transmissions of FRB 121102 continuously repeated in the above 157-day cycle caught the attention of the scientists.
FRB 121102 was determined to be emitted from a galaxy 3 billion light-years from Earth
According to Space.com, this finding provides important hints that help identify the source of radio waves. The existence of a repeatable FRB may be related to the motion of a neutron star, or from a black hole, said Dr. Kaustubh Rajwade at the University of Manchester, who led the research.
Specifically, the research team has proposed a number of theories about the origin and repetitive period of FRB 121102. For example, the periodic flare-ups of radio waves can be explained by swaying in the shaft. rotation of a neutron star with extremely strong magnetism. In addition, the repetition of FRB 121102 emission may also be related to the orbital motion of neutron stars in a binary star system.
This is an extremely special neutron star, with a dense core of remnants left over after a giant star created a supernova explosion. Their magnetic fields are 1,000 times stronger than ordinary neutron stars.
However, this hypothesis did not receive the approval of many astronomers. Typically, the swaying effects of neutron stars usually occur over a few weeks. This means that the hypothesis is consistent with FRB 180916, which has a 16-day emission cycle. Meanwhile, it still cannot explain why FRB 121102 has a much longer emission cycle, up to 157 days. This also means that astronomers still have a long way to go to unlock the mystery of the origin of the FRBs.
“This interesting finding shows just how little we know about the origin of FRB. We need other observations with a larger number of FRBs to have a clearer view of the source of the periodic signal“Dr Duncan Lorimer, assistant dean of the Department of Astrophysics at West Virginia University, is also a co-author of the study.
Refer to Space.com