Mysterious New Signals Detected by SETI: Unlocking the Strange Puzzle of Fast Radio Bursts
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- December 17, 2020
Fast Radio Bursts (FRBs) have long fascinated astronomers and astrophysicists due to their mysterious origins and intense energy. Recently, a team of researchers working with the Allen Telescope Array made an intriguing discovery. They detected a repeating FRB, named FRB 20220912A, which remained highly active for several months. This finding has opened up new possibilities for studying and understanding these enigmatic signals. In this article, we will delve into the characteristics of FRB 20220912A, its implications, and the significance of wideband observations in unraveling the mysteries of fast radio bursts.
The Discovery of FRB 20220912A
FRB 20220912A was initially discovered in the fall of 2022 and continued to emit signals for an extended period. The team of researchers detected a total of 35 FRBs from this source during their follow-up observations using the Allen Telescope Array. These observations covered 541 hours and focused on a bandwidth of 1344 MHz, primarily centered at 1572 MHz. Interestingly, all 35 FRBs were detected in the lower half of the band, with no detections in the upper half. The fluences of the detected FRBs ranged from 4-431 Jy-ms, with a median fluence of 48.27 Jy-ms.
During the two-month observing campaign, the researchers noticed an apparent decrease in the center frequency of the observed bursts. This decrease corresponded to a drop of $6.21/pm 0.76$ MHz per day. This finding raises intriguing questions about the underlying causes and mechanisms responsible for such variations in FRBs. Further investigations and modeling are needed to understand the physical processes that lead to these frequency shifts.
Contribution to the All-Sky FRB Rate
The researchers sought to determine the contribution of FRB 20220912A to the all-sky FRB rate. They predicted a cut-off fluence of this source to be consistent with the overall rate of FRBs observed across the sky. Based on their analysis, they found that FRB 20220912A significantly contributed to the all-sky FRB rate, albeit at a level of a few percent, for fluences of approximately 100 Jy-ms. This finding highlights the importance of studying and characterizing individual FRB sources to gain a comprehensive understanding of the overall FRB population.
Characteristic Timescales and Sub-Burst Periodicities
Interestingly, despite thorough analysis, the researchers found no evidence of strict periodicity in the bursts, even in the most evenly-spaced multi-component burst in the sample. This lack of periodicity suggests that the emission mechanism of FRBs is complex and likely involves multiple physical processes. Further studies and observations are necessary to unravel the intricate nature of these signals.
In conclusion The researchers emphasized the importance of wideband observations in the study of FRBs. By utilizing a wide frequency range, the team was able to capture a diverse set of FRB characteristics and spectrotemporal features. Wideband observations provide a comprehensive view of the signals, enabling researchers to examine frequency drifts, bandwidth correlations, and other important parameters. Such observations are crucial for comparing and evaluating various FRB models and theories.
