Astronomers have discovered a unique pattern in a repeating fast radio burst (FRB20220912A) observed by the SETI Institute. The discovery, described in Monthly Notices of the Royal Astronomical Society, challenges existing models of fast radio bursts.
Astronomers continue to unravel the mysteries of deep space signals by discovering a strange, never-before-seen phenomenon in a newly detected fast radio burst (FRB). New research reveals a never-before-seen pattern of repetitive fast radio burst behavior, providing new insights into these mysterious cosmic phenomena.
Fast radio bursts are millisecond-long, extremely bright radio flashes that usually originate from outside the Milky Way. Most of the time it happens only once, but some "repeaters" send out subsequent signals, adding to the curiosity surrounding their origins.
A new study published in Monthly Notices of the Royal Astronomical Society sheds new light on the mystery by discovering a "highly active" repeating FRB signal that behaves differently from any signal previously detected.
Scientists at the SETI Institute in California recorded 35 FRBs from one source, FRB20220912A, over a two-month period and discovered a fascinating pattern.
As with most repeating FRBs, each burst increases in frequency from high to low over time. But in FRB20220912A, the central frequency of the burst also dropped unprecedentedly. If the notes on a xylophone are converted into a sound spectrum, it sounds like a slide whistle in the universe. In it, most of the highest notes are heard in the first few seconds, while most of the lowest notes are heard in the last few seconds, as if a xylophone player was repeatedly striking the lowest bar on the instrument.
Theory and Discovery: One Step Closer to Understanding FRBs
Astronomers believe that at least some FRBs are produced by a type of neutron star called a magnetar - the highly magnetized core of a dead star - while other theories point to colliding neutron star binaries or merging white dwarfs.
"This work is exciting because it both confirms known properties of FRBs and discovers some new ones," said lead author Dr. Sofia Shaikh of the SETI Institute. "We are narrowing down the sources of FRBs, for example to extreme objects such as magnetars, but existing models cannot explain all the properties observed so far."
This audio is the data sound wave of 101 sub-bursts observed by ATA and analyzed in this work. The center frequency of each sub-burst maps to a xylophone note [in an octave of the Alydian scale]. There's a lot of dispersion in the notes, but most of the highest notes occur in the first few seconds, and most of the lowest notes in the last few seconds, as if a xylophone player was repeatedly striking the lowest bars available on the instrument. The researchers used statistical methods to verify whether this high-to-low trend was significant, and if ATA can be observed in a lower frequency range (the equivalent of "adding more notes" to the bottom of the xylophone), then this trend is likely to continue.
Researchers made the discovery after 541 hours of observations using the SETI Institute's Allen Telescope Array (ATA). They also tried to find patterns in the timing between bursts but found none, further illustrating the unpredictable and mysterious nature of these intense radio bursts.
Still, the latest research is a step closer to unlocking the secrets of FRBs, which produce as much energy in a thousandth of a second as the sun produces in an entire year.
Dr Sheikh added: "It is fantastic to be involved in the first ever FRB study using the Allen Telescope Array (ATA) - this work proves that new telescopes like the Allen Telescope Array with unique capabilities can unravel the mysteries of FRB science from a new perspective."
Compiled source: ScitechDaily