GCN Circular 27674
Subject
Fermi GBM observation of a flare from the magnetar SGR 1806-20
Date
2020-05-01T15:38:19Z (4 years ago)
From
Christian Malacaria at NASA-MSFC/USRA <cmalacaria@usra.edu>
C. Malacaria (NASA/MSFC/USRA) reports on behalf of the Fermi GBM Team:
"At 12:56:41 UT on 30 April 2020, the Swift Burst Alert Telescope (BAT)
triggered and located SGR 1806-20 (GCN 27672).
There was no Fermi-GBM onboard trigger around the event time.
However, the GBM targeted search [1], the most sensitive, coherent search
for sub-threshold signals, was run from +/-5 s around the trigger time,
and identified a significant signal whose location is consistent with SGR 1806-20.
The search was run down to a timescale of 4 ms and finds the most significant
timescale at 32 ms, with a log likelihood ratio of 50.
The flare spectrum is well fit by a blackbody model with a best-fit temperature
value of kT=7.5+/-1.1 keV. The event fluence (8-100 keV)
in this time interval is (1.5 +/- 0.3)E-7 erg/cm^2.
The spectral analysis results presented above are preliminary.
For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/
[1] Goldstein et al. 2019 arXiv:1903.12597"