Non-detection of repeat radio bursts from FRB 20250316A by the FAST telescope
ATel #17126; L. Qian (NAOC), J. R. Niu (NAOC), J. H. Cao (NAOC), Y. X. Huang (YNAO), X. Yang (PMO), J. H. Zhang (NAOC), Y. K. Zhang (NAOC), Y. H. Zhu (NAOC), Y. Li (PMO), Z. C. Pan (NAOC), C. Sun (NAOC), S. B. Zhang (PMO), H. Sun (NAOC), Y. Liu (NAOC), C. C. Jin (NAOC), X. F. Wu (PMO), W. M. Yuan (NAOC), B. Zhang (UNLV), W. W. Zhu (NAOC), P. Jiang (NAOC)
on 2 Apr 2025; 16:27 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Weiwei Zhu (zhuww@nao.cas.cn)
Subjects: Radio, Fast Radio Burst
We followed up the bright fast radio burst FRB20250316A from nearby galaxy NGC4141 detected by the CHIME team (ATel #17081 #17086, #17114) using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). FAST observed the target location six times, and a total of 13 hours and 5 minutes as part of a FAST Director Discretion Time and the FAST FRB key science project:
UTC 2025-03-17 16:45:00 to 2025-03-17 17:45:00
UTC 2025-03-18 15:38:00 to 2025-03-18 16:38:00
UTC 2025-03-18 16:50:00 to 2025-03-18 18:50:00
UTC 2025-03-20 17:28:00 to 2025-03-20 18:33:00
UTC 2025-03-21 15:39:00 to 2025-03-21 17:39:00
UTC 2025-03-22 16:56:00 to 2025-03-22 18:56:00
UTC 2025-03-23 17:00:00 to 2025-03-23 19:00:00
UTC 2025-03-24 14:58:00 to 2025-03-24 16:58:00
This FRB is particularly interesting because it is one of the brightest and from a nearby galaxy. The Einstein Probe (EP) team detected a candidate X-ray counterpart (ATel#17100) that was later proven to be likely unrelated to the FRB based on Chandra observations (ATel#17119).
We recorded and searched all 19 beam data from the FAST 19-beam receiver (1-1.5GHz) and found no signal with S/N>7 between the DM 140-180 pc cm^{-3}, equivalent to a burst fluence limit of about 17.5 mJy ms for a fiducial burst width of 1 ms. Our fluence limit corresponds to an upper limit of 1.7x10^{34} erg for the burst energy, assuming a source distance of 40 Mpc. Our result confirms the conclusion drawn by the hyperflash team (Atel#17124) that the FRB is unlikely to be an active repeater with a lower burst energy limit.
