Article by: Andacs Robert Eugen, on 22 June 2022, at 06:42 am Los Angeles time

Astronomers have detected a repeating mysterious radio wave coming from 3 billion light-years away. They probably come from a dwarf galaxy, according to astronomers.

These radio waves are different from those detected in recent years, according to new research. Radio wave explosions, or FRBs, are millisecond radio waves detected in space. They usually occur only once and are rarely repeated.

Astronomers have been able to track some explosions from radio waves to their home galaxies, but have not yet determined the true cause. Scientists are trying to find out more about the origins of these intense radio broadcasts to understand what causes them.

Astronomers detected the cosmic object named FRB 190520 when it launched a radio wave explosion on May 20, 2019. Researchers used China's FAST radio telescope and discovered a new explosion in data collected in November 2019. When they made further observations, astronomers noticed something unusual - the object emitted frequent and repeated bursts of radio waves.

In 2020, the team used VLA telescopes from the National Science Foundation and the Subaru Telescope in Hawaii to study these FRBs and found that the explosion came from the periphery of a distant dwarf galaxy.

The VLA's observations also showed that the cosmic object was constantly emitting weaker radio waves between repeated FRB emissions. This is very similar to another repetitive FRB: FRB 121102, discovered in 2016.

"Now we need to explain this double mystery and why FRBs and persistent radio sources sometimes come together," said Casey Law, co-author of the study and a researcher at the California Institute of Technology. "Is it common when these cosmic objects are 'young'? Or maybe the object that produces the explosions is a massive black hole that slowly swallows a neighboring star?" he wondered.

The researchers found that less than 5% of the hundreds of identified FRBs recur and only a few of them are active on a regular basis.

But FRB 190520 is the only persistent asset, which means it hasn't stopped at all since it was discovered, said Di Li, the study's author and head of the radio division of China's National Astronomical Observatories and FAST Operations Center.

Instead, FRB 121102 may not emit for months, Li said.

The latest findings raise several questions, as astronomers now wonder if there may be two types of FRBs.

"Are those that are repeated different from those that are not repeated? What about persistent radio broadcasting - is it commonplace? "Asks study co-author Kshitij Aggarwal, a doctoral student at the University of West Virginia.

There may be different mechanisms that cause radio explosions or their source may behave differently at different stages of evolution.

Scientists have previously hypothesized that fast radio explosions are caused by dense debris left behind by a supernova, called a neutron star, or stars with incredibly strong magnetic fields called magnets.

FRB 190520 is considered a possible "newborn" object because it is in a dense environment, Law concluded. This environment can be caused by the material released by a supernova, which led to the creation of a neutron star. As this material spreads, the explosions at FRB 190520 may decrease.