J/ApJ/955/142 Bursts from FAST obs. of FRB 20220912A in 2022 (Zhang+, 2023)
FAST observations of FRB 20220912A: burst properties and polarization
characteristics.
Zhang Y.-K., Li Di, Zhang B., Cao S., Feng Yi, Wang W.-Y., Qu Y.,
Niu J.-R., Zhu W.-W., Han J.-L., Jiang P., Lee K.-J., Li D.-Z., Luo R.,
Niu C.-H., Tsai C.-W., Wang P., Wang F.-Y., Wu Z.-W., Xu H., Yang Y.-P.,
Zhang J.-S., Zhou D.-J., Zhu Y.-H.
<Astrophys. J., 955, 142 (2023)>
=2023ApJ...955..142Z 2023ApJ...955..142Z
ADC_Keywords: Radio sources; Transient; Polarization
Keywords: Radio transient sources
Abstract:
We report the observations of FRB 20220912A using the
Five-hundred-meter Aperture Spherical radio Telescope (FAST). We
conducted 17 observations totaling 8.67hr and detected a total of
1076 bursts with an event rate up to 390hr-1. The cumulative energy
distribution can be well described using a broken power-law function
with the lower- and higher-energy slopes of -0.38±0.02 and
-2.07±0.07, respectively. We also report the L-band (1-1.5GHz)
spectral index of the synthetic spectrum of FRB 20220912A bursts,
which is -2.6±0.21. The average rotation measure value of the
bursts from FRB 20220912A is -0.08±5.39rad/m2, close to
0rad/m2 and was relatively stable over 2 months. Most bursts have
nearly 100% linear polarization. About 45% of the bursts have circular
polarization with Signal-to-Noise ratio >3, and the highest circular
polarization degree can reach 70%. Our observations suggest that
FRB20220912A is located in a relatively clean local environment with
complex circular polarization characteristics. These various behaviors
imply that the mechanism of circular polarization of FRBs likely
originates from an intrinsic radiation mechanism, such as coherent
curvature radiation or inverse Compton scattering inside the
magnetosphere of the FRB engine source (e.g., a magnetar).
Description:
FRB 20220912A has been observed since October 28th, 2022, using the
center beam of the Five-hundred-meter Aperture Spherical radio
Telescope (FAST) 19 beam receiver pointing to the coordinate of
RAJ2000=23:09:04.9,DEJ2000=+48:42:25.4 reported by the Deep Synoptic
Array (DSA-110; Ravi+ 2023ApJ...949L...3R 2023ApJ...949L...3R).
In 2022, 17 observations with a total of 8.67hr exposure time were
carried out. A high-cadence calibration signal was periodically
injected during the first minute of observation for the subsequent
flux and polarization calibration. The data were recorded in fits
format with a time resolution of 49.152us, covering the frequency
bandwidth from 1 to 1.5GHz with 4096 frequency channels.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
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23 09 04.89 +48 42 25.0 FRB 20220912A = FRB 20220912A
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 144 1076 The properties of the FRB 20220912A bursts
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See also:
J/other/PASA/33.45 : FRBCAT: The Fast Radio Burst Catalog (Petroff+, 2016)
J/ApJ/888/40 : Fast radio bursts with AstroSat/CZTI (Anumarlapudi+, 2020)
J/ApJS/257/59 : First CHIME/FRB Fast Radio Burst Cat. (CHIME/FRB Col.+, 2021)
J/ApJ/922/115 : Additional bursts at 1.4GHz for FRB 121102 (Aggarwal+, 2021)
J/other/Nat/598.267 : List of radio bursts (Li+, 2021)
J/MNRAS/500/655 : Gal. DM contribution to the extragalactic FRBs (Das+, 2021)
J/MNRAS/509/1227 : Hidden repeating fast radio bursts (Chen+, 2022)
J/MNRAS/511/1961 : New CHIME/FRB I catalog updates released (Hashimoto+, 2022)
J/A+A/675/A99 : FRBs search with Fermi-LAT (Principe+, 2023)
J/AJ/168/153 : Image-based blind search for FRBs in MWA 8yrs (Kemp+, 2024)
J/A+A/693/A279 : The Apertif fast radio burst sample (Pastor-Marazuela+, 2025)
J/A+A/698/A18 : Selected CHIME FRB sample (Zhang+, 2025)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [0/1075] Burst ID
6- 20 F15.9 d MJD [59880.4/59935.4] Modified Julian Date
(JD-2400000.5) (1)
22- 27 F6.2 pc/cm3 DM [212/230] Dispersion measure
29- 32 F4.2 pc/cm3 e_DM [0.03/8.2] Uncertainty in DM
34- 40 F7.1 mJy FluxPk [16.4/12251] Peak Flux, calculated within
500MHz bandwidth
42- 46 F5.1 mJy e_FluxPk [0.2/151] Flux Uncertainty
48- 52 F5.2 ms EW [0.09/33] Equivalent width
54- 59 F6.1 MHz FreqPk [868/1622] Peak Frequency obtained with
Gaussian fitting
61- 65 F5.1 MHz e_FreqPk [1.4/647] Uncertainty in PeakFreq
67- 72 F6.1 MHz BandWidth [28/1147] FWHM of Gaussian fitting
74- 80 F7.1 MHz e_BandWidth [3/38964] Uncertainty in BandWidth
82- 87 F6.3 Jy.ms Fluence [0.002/38] Fluence, calculated within
500MHz bandwidth
89- 93 F5.3 Jy.ms e_Fluence [0/0.5] Uncertainty in Fluence
95- 101 F7.2 10+29J E [0.13/2723] Energy, 10+36erg
103- 108 F6.1 rad/m2 RM [-122.1/79.5] Rotation measure
110- 114 F5.1 rad/m2 e_RM [0/218] Lower uncertainty in RM
116- 120 F5.1 rad/m2 E_RM [0/167] Upper uncertainty in RM
122- 126 F5.1 % LPol [27/243] Linear polarization degree
128- 132 F5.1 % e_LPol [0/106] Uncertainty in LPol
134- 139 F6.1 % CPol [-130/71.4] Circular polarization degree
141- 144 F4.1 % e_CPol [0/76] Uncertainty in CPol
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Note (1): Corresponding to the barycentrical arrival time at 1.5GHz
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Dec-2025