We’ve discovered a strange new signal from a rift that spans space and time.
In a total of 91 hours of observations, a recurring FRB source detected last year spewed 1,863 bursts in 82 hours.
This hyperactive behavior allows scientists to not only describe the galaxy the source is in and its distance from us, but also what the source is
The object, named FRB 20201124A, was detected by China’s Five Hundred Meter Aperture Spherical Radio Telescope (FAST) and described in a new paper led by astronomer Xu Heng of Peking University in China
So far, most evidence points to magnetars – a type of neutron star with an unusually strong magnetic field – as the source of this FRB emission. If FRB 20201124A is indeed from one of these savage cosmic beasts, it looks like an unusual monster.
“These observations put us back on the drawing board,” said Bing Zhang, an astrophysicist at the University of Nevada, Las Vegas
“It is clear that FRBs are more mysterious than we thought. Further observing campaigns at multiple wavelengths are needed to reveal more of the nature of these objects.”
Fast radio bursts have been a mystery to astronomers since they were first detected 15 years ago in archived data from 2001: Incredibly powerful peaks of radio emission that last only a blink of an eye. ‘eye.
Since then, other discoveries have been made: bursts of radio waves lasting a millisecond that release the energy of up to 500 million suns at that time. Most of those on record have only erupted once, making them difficult to learn (let alone understand) Very few have been observed repeating, which at least helps scientists track them down to find the host galaxy.
Then, in 2020, a breakthrough Fast radio bursts have been detected for the first time in the Milky Way, leading astrophysicists to trace the phenomenon back to magnetic activity
This last example of an extraordinary FRB is another example of a rare repeater In less than two months of observations, FRB 20201124A has provided astronomers with the largest sample of fast radio burst data containing polarization from any other FRB source
Polarization refers to the direction of light waves in three-dimensional space By examining how much this direction has changed since the light left the source, scientists can understand the environment in which the light travels. For example, a strong bias indicates a strong magnetic field environment.
From the extensive data provided by FRB 20201124A, astronomers were able to deduce that the source was a magnetar But it’s a bit weird. The way the polarization changes over time shows that the strength of the magnetic field and the density of the particles around the magnetar are changing.
“I liken it to filming the FRB source environment, and our film reveals a complex, dynamically changing magnetized environment that had never been imagined before,” Zhang explained.
“This environment is not directly expected for an isolated magnetar There may be something else near the FRB motor, perhaps a binary companion.”
According to the data, this companion could be a hot blue Be-type star, often seen in neutron star companions. The evidence for this is detailed in another paper led by astronomer Wang Fayin of Nanjing University in China
But there is something else. A type of neutron star, magnetars are the cores of massive stars that collapse under their own gravity after running out of fuel to burn and provide outward pressure.
Such stars burn up their fuel quickly and are short-lived, dissipating their outer material in a supernova as the core collapses
Due to their short life, these young magnetars are thought to be in regions where star formation is still in progress. The short life and death of stars create more clouds of matter, which in turn give rise to more stars It is a beautiful circle of cosmic life But FRB 20201124A was found in a galaxy very similar to the Milky Way There’s not much star formation at home, so there shouldn’t be any baby booms near our unusual new FRB friend.
However, FRB 20201124A is not the only source of FRBs found in galaxies relatively free of star formation.
A growing number of figures suggest we may be missing important information – a hole in our understanding of FRB magnetars, how they form and where they are found.
But characterizing the sources means we have a new place to look for answers Wang and his colleagues’ work suggests that neutron star-Be star binaries could be one of the best places to look for FRB signals