Scientists discover new properties of repeating fast radio burst 20220912A

Scientists from the SETI Institute have unveiled new revelations about Fast Radio Bursts (FRBs), a cosmic enigma, through the observation of the repeating FRB 20220912A using the SETI Institute’s upgraded Allen Telescope Array (ATA). These brief and intense flashes of radio waves from deep space have long intrigued researchers, with some FRBs repeating, adding complexity to their understanding. The ATA’s 541 hours of observation detected 35 FRBs from repeater FRB 20220912A, offering insights into their nature.

Dr. Sofia Sheikh, NSF MPS-Ascend Postdoctoral Fellow and lead author, expressed excitement about the findings, stating, “This work is exciting because it provides both confirmation of known FRB properties and the discovery of some new ones.” The observations, spanning a wide radio frequency range, highlighted intriguing patterns, with all 35 FRBs located in the lower part of the frequency spectrum, each displaying a unique energy signature.

Published in the Monthly Notices of the Royal Astronomical Society, the detailed findings shed light on the behaviors of FRBs. Noteworthy aspects include downward frequency drifting, a correlation between bandwidth and center frequency, and variations in burst duration over time. The team also reported a novel observation—a noticeable drop in the center frequency of bursts over the two months of observation, akin to an unexpected cosmic slide-whistle.

Moreover, the researchers utilized these observations to predict a cutoff point for FRB 20220912A’s brightest bursts, offering insights into its contribution to the overall cosmic signal rate. Remarkably, this specific object accounted for a few percent of all strong FRBs in the sky during the observation period. Dr. Sheikh emphasized the significance of using new telescopes like the ATA to provide fresh perspectives on unresolved mysteries in FRB science, suggesting that while progress has been made in narrowing down FRB sources to extreme objects like magnetars, some observed properties remain unexplained by existing models.

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. Credit: Sofia Z. Sheikh et al., SETI Institute (CC BY 4.0)

Delving into the time patterns of burst sequences, the study aimed to uncover repetitions within and between Fast Radio Bursts (FRBs). The findings revealed an absence of a clear pattern, underscoring the unpredictable nature of these celestial phenomena.

This research underscores the pivotal role of the ATA in unraveling the mysteries of FRBs. The ATA’s distinctive capability to record vast numbers of frequency channels simultaneously, even when widely separated, allows for instantaneous checks on FRBs. This includes constraining the FRB’s behavior at both high and low frequencies concurrently. Ongoing upgrades are poised to enhance these capabilities, enabling the ATA to detect fainter FRBs across even more frequencies simultaneously, solidifying its position at the forefront of advancing FRB understanding.

Dr. Wael Farah, SETI Institute ATA Project Scientist and co-author, expressed excitement about the ATA’s engagement in FRB research three years after refurbishment began. He highlighted the unique capabilities of the ATA, utilized in various research endeavors, including fast transients.

This milestone discovery represents a significant stride in the continuous pursuit of unraveling the secrets of extreme celestial objects. With each unique feature discovered in the cosmos, scientists move closer to comprehending the origins and nature of these captivating cosmic signals.

The comprehensive findings are detailed in “Characterization of the Repeating FRB 20220912A with the Allen Telescope Array,” authored by Sofia Z. Sheikh et al., soon to be published in Monthly Notices of the Royal Astronomical Society.

Source: SETI Institute

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