J/A+A/704/A25 FRB 20121102A parameters of the NRT bursts (Ng+, 2025)
Long-term monitoring of FRB 20121102A with the Nancay Radio Telescope and
multi-wavelength campaigns including INTEGRAL.
Gouiffes C., Ng C., Cognard I., Dennefeld M., Devaney N., Dhillon V.S.,
Guilet J., Laurent P., Le Floc'h E., Maury A.J., Nimmo K., Shearer A.,
Spitler L.G., Zarka P., Corbel S.
<Astron. Astrophys. 704, A25 (2025)>
=2025A&A...704A..25G 2025A&A...704A..25G (SIMBAD/NED BibCode)
ADC_Keywords: Radio sources ; GRB
Keywords: radiation mechanisms: non-thermal - methods: observational -
gamma rays: general - radio continuum: general
Abstract:
The origin(s) of fast radio bursts (FRBs), mysterious radio bursts
coming from extragalactic distances, remains unknown.
Multiwavelength observations are arguably the only way to answer this
question unambiguously.
We attempt to detect hard X-ray/soft gamma-ray counterparts to one of
the most active FRB sources, FRB 20121102A, as well as improve our
understanding of burst properties in radio through a long-term
monitoring campaign using the Nancay Radio Telescope (NRT).
Multiwavelength campaigns involving the International Gamma-ray
Astrophysics Laboratory (INTEGRAL) satellite, the Nancay Radio
Observatory, the optical telescopes at the Observatoire de
Haute-Provence, as well as Arecibo were conducted between 2017 and
2019. In 2017, the telescopes were scheduled to observe simultaneously
between September 24-29. We specifically used the Fast Response
Enhanced CCDs for the optical observations to ensure a high time
resolution. In 2019, we changed the strategy to instead conduct ToO
observations on INTEGRAL and other available facilities upon positive
detection triggers from the NRT.
In the 2017 campaign, FRB 20121102A was not in its burst active phase
periodic window. We obtain a 5σ optical flux limit of 12mJy ms
using the GASP and a 3σ limit from OHP T120cm R-band image of
R=22.2mag of any potential persistent emission not associated with
radio bursts. In the 2019 campaign, we have simultaneous INTEGRAL data
with at least 11 radio bursts from the NRT and Arecibo. We obtain a
5σ upper limit of 2.7x10-7erg/cm2 in the 25-400keV energy
range for contemporary radio and high energy bursts, and a 5σ
upper limit of 3.8x10-11erg/cm2 for permanent emission in the
25-100keV energy range. In addition, we report on the regular
observations from NRT between 2016-2020, which account for 120
additional radio bursts from FRB 20121102A. We observe temporal
dispersion measure (DM) variations at a level of
{DELTA}DM~+2.04(4)pc/cm3/yr, in broad agreement with the literature.
We also present an updated fit of the periodic active window, the
emission bandwidth and the burst width distribution.
Description:
We report 131 radio bursts detected by the NRT between 2016-2019,
which provides a more precise measurement of the activity periodic
window of 158.1(3) days.
Objects:
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RA (2000) DE Designation(s)
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05 31 58.69 +33 08 52.5 FRB 20121102A = FRB 121102
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 86 131 Parameters of the NRT bursts
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 16 F16.10 d Time Burst time (MJD) (1)
19- 30 F12.10 d e_Time Burst time error
33- 35 A3 --- n_Time Note on MJD (2)
38- 43 F6.2 pc/cm3 DM ?=- Dispersion measure
45- 48 F4.2 pc/cm3 e_DM ?=- Dispersion measure error
50- 55 F6.3 ms Width Width
57- 61 F5.3 ms e_Width Width error
63- 67 F5.2 Jy.ms Fluence ?=- Fluence (measured independently)
69- 72 F4.2 Jy.ms e_Fluence ?=- Fluence error
74- 82 A9 MHz Range Emitting range
84- 86 I3 MHz Bandwidth ? Emitting bandwidth
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Note (1): The MJDs of the burst arrival times are not barycentric corrected.
Note (2): Note as follows:
d = These are the 7 NRT bursts that are concurrently with INTEGRAL
observations
* = This is the burst shown in Fig. 10.
dd = These are the 4 NRT bursts that happened during the INTEGRAL Crab
calibration scans
P = The raw data of these two bursts are lost, we are not able to derive
the missing parameters
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Acknowledgements:
Cherry Ng, cherry.ng-guiheneuf(at)cnrs-orleans.fr
(End) Patricia Vannier [CDS] 12-Nov-2025