Nine Bursts in Three Days from a Newly Discovered Repeating Source of Fast Radio Bursts
ATel #15679; Ryan Mckinven (McGill, MSI) on behalf of the CHIME/FRB Collaboration
on 15 Oct 2022; 00:03 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Aaron Pearlman (aaron.b.pearlman@physics.mcgill.ca)
Subjects: Radio, Transient, Fast Radio Burst
Referred to by ATel #: 15691, 15693, 15695, 15696, 15699, 15713, 15716, 15720, 15723, 15727, 15733, 15734, 15735, 15757, 15758, 15791, 15806, 15817, 16130, 16196
We report a period of high activity from a new repeating FRB source (FRB 20220912A) discovered by CHIME/FRB on 2022-09-12 07:45:51 UTC at 400 MHz. We have detected a total of 9 radio bursts from the source in the past three days of observations and 3 additional bursts were detected last month, prior to an extended period of maintenance during which the CHIME/FRB detection system was offline. Given the limited daily exposure of CHIME to transiting sources (10-15 minutes), the burst rate may be as high as 200-300 bursts per day at ~Jy ms fluence thresholds.
| Burst Arrival Time |
Detection S/N |
| (UTC) |
|
| 2022-09-12 07:45:51 |
11.79 |
| 2022-09-15 07:31:38 |
8.62 |
| 2022-09-15 07:32:00 |
8.63 |
| 2022-10-12 05:43:20 |
9.35 |
| 2022-10-12 05:50:53 |
29.04 |
| 2022-10-12 05:53:05 |
11.39 |
| 2022-10-13 05:40:48 |
13.77 |
| 2022-10-13 05:41:19 |
8.41 |
| 2022-10-13 05:41:39 |
9.70 |
| 2022-10-13 05:49:29 |
15.79 |
| 2022-10-14 05:38:29 |
11.61 |
| 2022-10-14 05:39:39 |
11.24 |
The above UTC burst times from the real-time detection system are approximate and subject to optimization following proper burst fitting.
The DM of the source is 219.46(4) pc cm^-3, based on voltage data from the brightest burst. The maximum Galactic DM contribution from the NE2001/YMW16 models is ~125/122 pc cm^-3. Note that the excess DM, after subtracting the line-of-sight Galactic contribution, is < 100 pc cm^-3.
The best-fit localization was performed on the voltage data of the brightest burst, placing the source at RA (J2000): 347.29(4) deg, Dec (J2000): +48.70(3) deg, with errors quoted at 90% uncertainty (Michilli et al. 2021 ApJ, 910, 147).
An upper limit on the redshift of the source was determined to be z ~ 0.089 (95% upper limit), using the same priors as reported in Bhardwaj et al. 2021 ApJL, 919, L24.
A preliminary search of the Pan-STARRS and WISE imaging fields shows an 8th magnitude star is present near the localization uncertainty region, however several potential hosts are visible. In the Pan-STARRS DR1 imaging and catalog, perhaps the most visually promising potential host within the localization window is at RA (J2000), Dec (J2000) = 347.2702, 48.7066 deg with Kron mag r=19.7 (Magnier et al. 2020 ApJS, 251, 1).
The brightest burst displays a linear fractional polarization that is consistent with 100% and a small RM of +0.6(1) rad m^-2. The estimated Galactic RM contribution along this sightline is -15.9(9.2) rad m^-2 (Hutschenreuter et al. 2022 A&A, 657, A23), indicating little RM contribution from the host galaxy ISM or local environment.
The link below shows the waterfall plot for the brightest event, dedispersed to optimize peak S/N. A more detailed study of these events is underway.
We encourage rapid multi-wavelength follow-up, especially radio interferometric observations to localize FRB 20220912A.
Waterfall Plot of Bright Burst from FRB 20220912A
