Recent Soft Gamma Repeater Activity from SGR 1806-20
ATel #16928; David M. Palmer (LANL) on behalf of the Swift Team
on 29 Nov 2024; 22:12 UT
Credential Certification: David M. Palmer (palmer@lanl.gov)
Subjects: X-ray, Gamma Ray, Soft Gamma-ray Repeater, Magnetar
Swift/BAT has detected recent SGR bursts from soft gamma-ray repeaters: SGR 1806-20 (the subject of this ATel) and SGR 1E 1841-045 / Kes 73 (ATel #16927).
The current SGR 1806-20 activity began in 2024 September (ATel #16838). Previously, it was last seen by BAT in March 2023.
The recent burst history for SGR 1806-20 as seen by BAT, omitting bursts from 2023 and earlier, is shown in the following table.
| Time (UTC) |
Trigger duration (s) |
Fluence (Crab s) |
|
| 2024-09-19T09:17:38 | 0.032 | 0.47 ± 0.06 | |
| 2024-09-28T01:09:28 | 0.016 | 0.50 ± 0.05 | |
| 2024-10-30T22:36:35 | 0.008 | 0.28 ± 0.03 | |
| 2024-11-19T20:37:06 | 0.032 | 1.02 ± 0.15 | |
| 2024-11-19T20:38:29 | 0.256 | 3.85 ± 0.36 | |
| ± | | | |
| | | |
Fluences are nominally in Crab-seconds, 15-50 keV, adjusted for instrument exposure.
The calibration is approximate and does not take spectral properties into account,
so fluence values should only be used for qualitative comparison among bursts from this and other SGRs as measured by BAT.
