GCN Circular 27659
Subject
Fermi GBM observation of a bright flare from magnetar SGR 1935+2154
Date
2020-04-28T02:28:30Z (4 years ago)
From
Cori Fletcher at USRA <cfletcher@usra.edu>
C. Fletcher (USRA) reports on behalf of the Fermi GBM Team:
"At 18:26:20.16 UT on 27 April 2020, the Fermi Gamma-Ray Burst
Monitor triggered on a bright, SGR-like burst from the direction
of the magnetar SGR 1935+2154 (trigger 609704785/ 200427768),
which was also detected by the Swift/BAT (Barthelmy et al. 2020, GCN 27657).
The burst has a duration (T90) of ~2 seconds in the energy range 10-200 keV.
It is well-fit by a power law function with an exponential
high-energy cutoff. The power law index is 0.02 +/- 0.68 and
the cutoff energy, parameterized as Epeak, is 27.2 +/- 2.5 keV.
The event fluence (10-200 keV) from T0-1.024 to T0+1.024 is (2.0 +/- 0.2)E-7 erg/cm^2.
The average photon flux in the 10-200 keV band during this period is 2.5 +/- 0.2
ph/s/cm^2.
Fermi GBM also subsequently triggered on multiple bursts from SGR 1935+2154 on
27 April 2020 with a fraction of these being misclassified as GRBs.
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/�