A Sudden Period of High Activity from Repeating Fast Radio Burst 20201124A
Name
Lanman_2022_ApJ_927_59.pdf
Description
Published version
Size
2.07 MB
Format
Adobe PDF
Checksum (MD5)
dca97412f0f729a64d6f0afeb03167f6
Author(s)
Masui, Kiyoshi
Date Issued
March 1, 2022
Journal
The Astrophysical Journal
Publisher
American Astronomical Society
Citation
Masui, Kiyoshi. 2022. "A Sudden Period of High Activity from Repeating Fast Radio Burst 20201124A." The Astrophysical Journal, 927 (1).
Version
Final published version
Abstract
Abstract
The repeating FRB 20201124A was first discovered by CHIME/FRB in November of 2020, after which it was seen to repeat a few times over several months. It entered a period of high activity in April of 2021, at which time several observatories recorded tens to hundreds more bursts from the source. These follow-up observations enabled precise localization and host-galaxy identification. In this paper, we report on the CHIME/FRB-detected bursts from FRB 20201124A, including their best-fit morphologies, fluences, and arrival times. The large exposure time of the CHIME/FRB telescope toward the location of this source allows us to constrain its rates of activity. We analyze the repetition rates over different spans of time, constraining the rate prior to discovery to <3.4 day−1 (at 3σ), and demonstrate a significant change in the event rate following initial detection. Lastly, we perform a maximum-likelihood estimation of a power-law luminosity function, finding a best-fit index α = −4.6 ± 1.3 ± 0.6, with a break at a fluence threshold of F min ∼ 16.6 Jy ms, consistent with the fluence completeness limit of the observations. This index is consistent within uncertainties with those of other repeating FRBs for which it has been determined.
The repeating FRB 20201124A was first discovered by CHIME/FRB in November of 2020, after which it was seen to repeat a few times over several months. It entered a period of high activity in April of 2021, at which time several observatories recorded tens to hundreds more bursts from the source. These follow-up observations enabled precise localization and host-galaxy identification. In this paper, we report on the CHIME/FRB-detected bursts from FRB 20201124A, including their best-fit morphologies, fluences, and arrival times. The large exposure time of the CHIME/FRB telescope toward the location of this source allows us to constrain its rates of activity. We analyze the repetition rates over different spans of time, constraining the rate prior to discovery to <3.4 day−1 (at 3σ), and demonstrate a significant change in the event rate following initial detection. Lastly, we perform a maximum-likelihood estimation of a power-law luminosity function, finding a best-fit index α = −4.6 ± 1.3 ± 0.6, with a break at a fluence threshold of F min ∼ 16.6 Jy ms, consistent with the fluence completeness limit of the observations. This index is consistent within uncertainties with those of other repeating FRBs for which it has been determined.
MIT Department
MIT Kavli Institute for Astrophysics and Space Research
Massachusetts Institute of Technology. Department of Physics
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Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.3847/1538-4357/ac4bc7
