Astronomers stumble upon intriguing characteristics in enigmatic fast radio bursts revisited
The first fast radio burst (FRB) was discovered in 2007, and since then, hundreds of these brief, intense events have been found at distant locations in the universe. Previous research suggested that these explosions could produce as much energy in a thousandth of a second as the Sun does in a year or longer.
However, astronomers remain puzzled about what triggers these phenomena. Now, researchers have noticed an unusual, never-before-seen pattern in a newly discovered, repeating fast radio burst named FRB 20220912A. The findings, reported in a study published in the Monthly Notices of the Royal Astronomical Society on Wednesday, offer invaluable clues to the origins of this fascinating enigma and give rise to new mysteries waiting to be solved.
Scientists discovered the burst using the Allen Telescope Array (ATA) of the SETI Institute in California, which boasts 42 antennas at the Hat Creek Radio Observatory in the Cascade Mountains. The team spotted 35 quick radio signals originating from a single source within two months.
Many FRBs emit radio waves that last no more than a few milliseconds before fading away, making their observation challenging. Yet, it is known that some FRB bursts recur and generate subsequent bursts, enabling scientists to track signals back to distant galaxies.
At first glance, FRB 20220912A seems similar to other known "repeaters," switching between higher and lower frequencies with each identified burst. But closer examination of the signal revealed something unusual: The central frequency of the burst noticeably decreased, much like a celestial whistle.
This decline was more pronounced when researchers used a xylophone to translate the signal into sound, with the high notes representing the start of the burst and the low notes representing its end. The team sought to determine if a pattern existed between the individual bursts, similar to what is observed in some other known, repeating fast radio bursts. However, they were unable to find any recurring pattern in FRB 20220912A, adding another layer of uncertainty to the inevitable unpredictability of cosmic events.
"This research is intriguing because it confirms some established characteristics of FRBs while also revealing new ones that demand explanation," said Dr. Sofia Sheikh, lead author of the study and a national scientist at the SETI Institute, in a statement.
A Labyrinth of Questions
Researchers speculate that some fast radio bursts may originate from magnetars, the strongly magnetized cores of dead stars. Other studies point to neutron star collisions or white dwarfs, known as collapsed stars, as potential culprits.
"We constrain the sources of fast radio bursts to extreme objects like magnetars, but existing models fail to explain all the observed properties of these events.
Source:
: Enrichment Data: Fast radio bursts (FRBs) continue to be a topic of curiosity and research, with multiple theories attempting to explain their origins. Some research suggests that:
- Magnetospheric processes might be responsible for some FRBs, particularly those that originate near compact objects like neutron stars.
- Polarization patterns have been observed in certain FRBs, which suggests the presence of highly magnetized, rotating neutron stars.
- Repeating FRBs have been detected and studied, shedding light on their origins. For example, FRB 20240209A originated from an ancient, dead galaxy's edge region, challenging the notion that neutron stars are only found in younger environments.
- The possibility of magnetic flares as the cause of FRBs has been proposed, but the discovery of old neutron stars generating FRBs challenges this theory, suggesting that FRBs can occur in older environments than first believed.
By understanding this intricate interplay of enigmatic bursts and the complex phenomena they represent, astronomers hope to unlock the mysteries of the universe that remain shrouded in the cosmic veil.
