A New Mystery Radio Signal Is Repeating From An Ancient Dwarf Galaxy, And It's A Weird One

A newly identified source of recurring fast radio bursts has added to the enigma surrounding the origin of these intense outbursts.

The source, identified as FRB 190520B and spotted for the first time in 2019, appears to frequently emit millisecond-long bursts of powerful radio waves.

This has permitted astronomers to conduct assessments that disclose details about where it comes from in the Universe, and the space around it. These findings indicate that there is likely more than one mechanism in the vast universe capable of causing these bizarre explosions.

Fast radio bursts (FRBs) are, as their name indicates, very short bursts of radio wavelength radiation (lasting barely milliseconds in duration).

The vast majority originate from distant galaxies (just one source has been found in the Milky Way), and they emit as much energy in a second as 500 million Suns.

Most of these outbursts have only been spotted once: they appear out of nowhere, burst once, and then disappear. This makes them almost impossible to predict, as well as very challenging to track and examine.

But a handful of repeated sources (actually, three at this point) give a tantalizing possibility to comprehend what's going on. Maybe.

The fact that the FRB identified in the Milky Way originated from a magnetar shows that at least some FRBs are triggered by magnetar eruptions. However, there are still many unknowns.

"Are those that repeat different from those that don't?" says astrophysicist Kshitij Aggarwal from West Virginia University.

The FRB 190520B discovery signal came to Earth in May of 2019, was detected by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China, and was discovered in November of the same year.

Observations conducted at the same place in the sky confirmed that the source was recurring.

More observations with the Karl G. Jansky Very Large Array of the National Science Foundation revealed a remarkable collection of traits. Nearly 4 billion light-years distant, the signals originated from the periphery of a very ancient dwarf galaxy.

In between radio bursts, the source seems to emit a weaker radio signal. This indicates that the quick radio bursts originate from an unidentified compact persistent radio source.

If you are an expert in fast radio bursts, this may sound familiar. These features are similar to FRB 121102, another well-known recurring rapid radio burst.

This was the first FRB ever tracked to a source, which was the fringes of a very ancient dwarf galaxy located 3 billion light-years distant. Likewise, it is connected to a compact persistent radio source.

"Now we have two like this, and that brings up some important questions," says astronomer Casey Law of Caltech.

We do not know, for instance, if FRBs with energy too low to be detected reoccur. The finding of FRB 190520B, however, is consistent with the theory that there are at least two separate processes for manufacturing the bursts.

This might indicate that the separate bursts are released by distinct things, or by the same kind of entity at various phases of its development.

So far the exact cause of these repeating radio signals is unknown and some scientists even bring up the possibility of Aliens involved somewhere in the process but as of now, there's no solid proof.

Reference(s): Peer-Reviewed Research, EurekaAlert