[vsnet-grb-info 27955] Fermi GBM observation of a bright burst from magneta

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30058
SUBJECT: Fermi GBM observation of a bright burst from magneta
DATE:    21/05/20 13:08:44 GMT
FROM:    Rachel Dunwoody at UCD  <rachel.dunwoody at ucdconnect.ie>

S. Lesage (UAH) reports on behalf of the Fermi GBM Team:

"At 19:22:03.94 UT on 19 May 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located a bright, SGR-like burst from the direction of
the magnetar SGR J1745−2900 (trigger 643144928/210519807).

The GBM on-ground location is consistent with the known position of the SGR.

The burst has a duration (T90) of about 0.3 s (10-300 keV).

It is adequately fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.6 +/- 0.5 and
the cutoff energy, parameterized as Epeak, is 37 +/- 4 keV.

The event fluence (10-300 keV) from T0-0.256s to T0+0.064s is
(1.4 +/- 0.1)E-07 erg/cm^2. The average photon flux in the
10-300 keV band during this period is 9.5 +/- 0.7 ph/s/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/"