Scientists from the SETI Institute have revealed new insights into the enigma of Fast Radio Bursts (FRBs).
Dynamic spectra (or “waterfall” plots) for all the bursts from FRB 20220912A detected using the Allen Telescope Array, the frequency-averaged pulse profiles, and the time-averaged spectra. The red-shaded regions in the time series plots denote the time span of the defined sub-bursts, with red vertical lines demarcating adjacent sub-burst. Image Credit: SETI Institute
The detailed observation and discovery of the recurrent FRB 20220912A, conducted with the upgraded Allen Telescope Array (ATA) at the SETI Institute, have illuminated the characteristics of these celestial signals.
Fast Radio Bursts are fleeting and intense bursts of radio waves originating from the depths of space. While the majority are singular occurrences, certain FRBs, referred to as "repeaters," emit signals multiple times, intensifying the mystery surrounding their origin.
During an extensive 541-hour observation period, researchers identified 35 FRBs emanating from the repeater FRB 20220912A. Utilizing the ATA, the observations spanned a broad radio frequency range and uncovered intriguing patterns. Notably, all 35 FRBs were located in the lower portion of the frequency spectrum, each exhibiting a distinctive energy signature.
This work is exciting because it provides both confirmation of known FRB properties and the discovery of some new ones.
Dr. Sofia Sheikh, Study Lead Author and NSF MPS-Ascend Postdoctoral Fellow, SETI Institute
Sheikh added, “We're narrowing down the source of FRBs, for example, to extreme objects such as magnetars, but no existing model can explain all of the properties that have been observed so far. It has been wonderful to be part of the first FRB study done with the ATA -- this work proves that new telescopes with unique capabilities, like the ATA, can provide a new angle on outstanding mysteries in FRB science.”
Recently published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS), the detailed findings highlight the fascinating behaviors exhibited by Fast Radio Bursts (FRBs).
These enigmatic signals showcase characteristics such as downward frequency drifting, a correlation between bandwidth and center frequency, and variations in burst duration over time.
In a noteworthy revelation, the research team observed a previously unreported phenomenon: a distinct decrease in the center frequency of bursts throughout the two-month observation period, akin to an unexpected cosmic slide-whistle.
Furthermore, the researchers utilized these observations to anticipate a cut-off point for the brightest bursts from FRB 20220912A, providing insights into its contribution to the overall cosmic signal rate. Remarkably, this particular object was found to be responsible for a notable percentage of strong FRBs in the sky during the observation period.
The study delved into the temporal patterns of burst sequences, exploring potential repetitions within and between FRBs. However, no discernible pattern emerged, underscoring the unpredictable nature of these celestial phenomena.
This research underscores the pivotal role of the Allen Telescope Array (ATA) in deciphering the mysteries of FRBs. The ATA's unique capability to simultaneously record vast numbers of frequency channels, even when widely separated, enables instantaneous checks on FRBs, offering insights into their behavior across a broad spectrum.
Ongoing upgrades promise enhanced capabilities, allowing the ATA to detect fainter FRBs at an even wider range of frequencies, ensuring its continued leadership in advancing our comprehension of FRBs.
It is exciting to see the ATA engaged in FRB research three years after its upgrade program started. The ATA boasts unique capabilities that are being put at use in many research endeavors including fast transients.
Dr. Wael Farah, Study Co-Author and ATA Project Scientist, SETI Institute
This pivotal breakthrough represents a noteworthy stride in the continual pursuit of unraveling the mysteries surrounding extreme celestial entities.
As researchers persist in their exploration of the cosmos, each distinctive feature unearthed serves to bring us one step closer to comprehending the origins and characteristics of these enthralling cosmic signals.