CHIME/FRB Detection of Another Bright Radio Burst from SGR 1935+2154
ATel #15792; Aaron B. Pearlman (McGill University; Trottier Space Institute at McGill University) on behalf of the CHIME/FRB Collaboration
on 5 Dec 2022; 20:18 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Aaron Pearlman (aaron.b.pearlman@physics.mcgill.ca)
Subjects: Radio, X-ray, Gamma Ray, Neutron Star, Soft Gamma-ray Repeater, Star, Transient, Pulsar, Fast Radio Burst, Magnetar
Referred to by ATel #: 15794
The CHIME/FRB Collaboration reports the detection of another bright radio burst from the direction of the known Galactic magnetar SGR 1935+2154 (see ATels #
15681, #
15697, #
15707 for other recent radio detections).
This latest, single-peaked event occurred at 2022-12-01 22:06:59.079 UTC (topocentric arrival time at infinite frequency), and it was detected in multiple beams. Of the beams where a detection was registered, the highest signal-to-noise ratio was 31.5. A preliminary best-fit dispersion measure (DM) of 332.85 +/- 0.03 pc cm^-3 was obtained from a joint Markov chain Monte Carlo (MCMC) fit to the total intensity data using the fitburst burst fitting software package. This DM measurement is consistent with past DM measurements of radio bursts from the magnetar (e.g., see CHIME/FRB Collaboration 2020, Nature, 587, 54).
At the time of this recently detected radio burst, the magnetar was 12.0 degrees east of CHIME's meridian, indicating a far side-lobe detection and consistent with the notched frequency structure observed in the dynamic spectrum. However, the preliminary sky localization of the source is consistent with the previously detected position of SGR 1935+2154. A preliminary estimate (lower limit) of the burst's fluence is 14 kJy ms at 600 MHz.
Refined measurements of the burst's arrival time, DM, and fluence are in progress.
We strongly encourage additional observations at all wavelengths.
Dynamic spectrum of a bright radio burst detected from SGR 1935+2154 with CHIME/FRB