Mysterious radio pulses from outer space explained

Astronomers have tied the origin of Fast Radio Bursts - brief yet brilliant eruptions of cosmic radio waves - to a highly magnetised, gas-filled region of space, providing a new hint in the decade-long quest to explain the mysterious radio pulses.
While only 16 have ever been recorded, scientists believe there could be thousands of Fast Radio Bursts (FRBs) a day.
Spotting bursts requires painstaking analysis of data recorded during radio astronomy observations. The newly identified FRB was discovered using data-mining software developed by scientists from the University of British Columbia in Canada and University of KwaZulu-Natal in Durban, South Africa.

The software enabled the astronomers to find bursts more quickly within the data.
As they sifted through the detailed data, the researchers discovered that the FRB exhibited Faraday rotation, a corkscrew-like twist radio waves acquire by passing through a powerful magnetic field.
"We now know that the energy from this particular burst passed through a dense magnetised field shortly after it formed," said Kiyoshi Masui, an astronomer with the University of British Columbia who developed the data-mining software.

Additional analysis of the signal showed that it also passed through two distinct regions of ionised gas, called screens, on its way to Earth. By using the interplay between the two screens, the astronomers were able to determine their relative locations.

The strongest screen is very near the burst's source - within a hundred thousand light-years - placing it inside the source's galaxy. Only two things could leave such an imprint on the signal - a nebula surrounding the source or a galactic centre.
"This significantly narrows down the source's environment and type of event that triggered the burst - and means the source of the pulse likely resides within a star-forming nebula or the remnant of a supernova," Masui added.
"Taken together, these remarkable data reveal more about an FRB than we have ever seen before and give us important constraints on these mysterious events," she said.

The FRB - dubbed FRB 110523 - originated no more than six billion light-years from Earth.
The findings were published in the journal Nature.