Source of 'alien' signals from space close to identified | More

First discovered in 2007, fast radio bursts, or FRBs, last only a millisecond.

Some experts have suggested they could come from an extraterrestrial life form attempting to make contact with Earth.

The exact cause and origins of FRBs remain unconfirmed.

What scientists previously thought about their origin is just the tip of the iceberg, according to new research led by astronomers at the University of Toronto in Canada.

The study, published in The Astrophysical Journal, details the properties of polarized light from 128 non-repeating FRBs – those from sources that have produced only a single burst to date.

The research team says they appear to come from galaxies like our own Milky Way, with modest densities and magnetic fields.

Previous studies of FRBs have focused on much smaller samples of hyperactive repetitive sources that, in contrast, appear to originate from dense, extremely magnetized environments.

Only about three percent of known FRBs repeat, coming from a source that has produced several bursts since their discovery.

Most radio telescopes can only see small dots in the sky, making it easier to focus on repeated FRBs whose positions are known.

But CHIME can survey an extremely large area of ​​the sky to detect both repeating and non-repeating FRBs.

The study's lead author, Ayush Pandhi, a doctoral student at the University of Toronto, said: “This was the first look at the other 97%.

“This allows us to reconsider what we think about FRBs and see how repetitive and non-repetitive FRBs may be different.”

While more than 1,000 FRBs have been documented since they were first detected 17 years ago, scientists do not yet know exactly where or how they are produced.

They also wondered whether repetitive and non-repetitive FRBs came from similar environments.

Pandhi said: “This is a new way of analyzing the data we have on FRBs.

“Instead of just looking at the brightness of an object, we also look at the angle of the light’s vibrating electromagnetic waves.

“This gives you additional information about how and where this light is produced, and what it went through on its journey to us over several million light years.”

He explained that all light propagates in waves that we interpret as different colors, depending on the length between its peaks and valleys.

Much of the light in the universe travels in wavelengths that the human eye cannot see, including light from FRBs, but radio telescopes like CHIME can.

Pandhi said: “Polarized light is made up of waves that vibrate in a single plane – vertically, horizontally or at some other angle in between.

“The direction in which the light from FRBs is polarized changed in two ways: with time and with the color of the light.

“These changes may explain how an FRB could have been produced and what type of material it passes through on its journey to Earth.

“Studying how the polarization direction changes for different colors of light can tell us about the local density of where an FRB is produced and the strength of the magnetism present there.”

To determine what FRBs are and how they are produced, he said scientists need to understand their local environment.

Pandhi said: “This study concludes that most FRBs, those that do not repeat, are unlike the few repetitive sources that have been studied previously. »

He added: “This suggests that this sample is either a distinct population or more evolved versions of the same population that come from a less extreme environment with a lower breakup rate.”