CaltechAUTHORS
Published December 2022 | Version public
Journal Article Metadata-only

FAST Observations of an Extremely Active Episode of FRB 20201124A. IV. Spin Period Search

Creators

  • 1. ROR icon National Astronomical Observatories
  • 2. ROR icon University of Chinese Academy of Sciences
  • 3. ROR icon Beijing Normal University
  • 4. ROR icon Peking University
  • 5. ROR icon University of KwaZulu-Natal
  • 6. ROR icon Zhejiang Lab
  • 7. ROR icon California Institute of Technology
  • 8. ROR icon Nanjing University
  • 9. ROR icon University of Science and Technology of China

Abstract

We report the properties of more than 800 bursts detected from the repeating fast radio burst (FRB) source FRB 20201124A with the Five-hundred-meter Aperture Spherical radio Telescope during an extremely active episode on UTC 2021 September 25th-28th in a series of four papers. In this fourth paper of the series, we present a systematic search of the spin period and linear acceleration of the source object from both 996 individual pulse peaks and the dedispersed time series. No credible spin period was found from this data set. We rule out the presence of significant periodicity in the range between 1 ms and 100 s with a pulse duty cycle <0.49 ± 0.08 (when the profile is defined by a von-Mises function, not a boxcar function) and linear acceleration up to 300 m s⁻² in each of the four one-hour observing sessions, and up to 0.6 m s⁻² in all 4 days. These searches contest theoretical scenarios involving a 1 ms–100 s isolated magnetar/pulsar with surface magnetic field <10¹⁵ G and a small duty cycle (such as in a polar-cap emission mode) or a pulsar with a companion star or black hole up to 100 M_⊙ and P_b > 10 hr. We also perform a periodicity search of the fine structures and identify 53 unrelated millisecond-timescale "periods" in multi-components with the highest significance of 3.9σ. The "periods" recovered from the fine structures are neither consistent nor harmonically related. Thus they are not likely to come from a spin period. We caution against claiming spin periodicity with significance below ∼4σ with multi-components from one-off FRBs. We discuss the implications of our results and the possible connections between FRB multi-components and pulsar microstructures.

Additional Information

We thank the referee, Scott Ransom, for helpful comments. This work made use of data from the FAST, a Chinese national mega-science facility, built and operated by the National Astronomical Observatories, Chinese Academy of Sciences. This work is supported by the National SKA Program of China (Nos. 2020SKA0120200 and 2020SKA0120100), the National Natural Science Foundation of China (Grant Nos. 12041303, 11873067 and 12041304) the National Key R&D Program of China (Nos. 2017YFA0402600, 2021YFA0718500 and 2017YFA0402602), the CAS-MPG LEGACY project, the Max-Planck Partner Group, and the Key Research Project of Zhejiang Lab (No. 2021PE0AC0). J. L. Han is supported by the National Natural Science Foundation of China (NSFC, Nos. 11988101 and 11833009) and the Key Research Program of the Chinese Academy of Sciences (Grant No. QYZDJ-SSW-SLH021); D. J. Zhou is supported by the Cultivation Project for the FAST scientific Payoff and Research Achievement of CAMS-CAS.

Additional details

Identifiers

Eprint ID
118829
Resolver ID
CaltechAUTHORS:20230117-372591200.32

Funding

National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
2020SKA0120200
National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
2020SKA0120100
National Natural Science Foundation of China
12041303
National Natural Science Foundation of China
11873067
National Natural Science Foundation of China
12041304
National Key Research and Development Program of China
2017YFA0402600
National Key Research and Development Program of China
2021YFA0718500
National Key Research and Development Program of China
2017YFA0402602
Max Planck Society
Key Research Project of Zhejiang Laboratory
2021PE0AC02
National Natural Science Foundation of China
11988101
National Natural Science Foundation of China
11833009
Chinese Academy of Sciences
QYZDJ-SSW-SLH021

Dates

Created
2023-02-10
Created from EPrint's datestamp field
Updated
2023-02-10
Created from EPrint's last_modified field