[vsnet-grb-info 25352] GRB 200325A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27453
SUBJECT: GRB 200325A: Fermi GBM observation
DATE:    20/03/27 01:55:20 GMT
FROM:    Peter Veres at UAH  <veresp at gmail.com>

P. Veres (UAH), C. M. Hui (NASA/MSFC), C. Meegan (UAH) and J. Wood
(NASA/MSFC) report on behalf of the Fermi GBM Team:

"At 03:18:31.74 UT on 25 March 2020, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered
and located GRB 200325A (trigger 606799116 / 200325138)
which was also detected by the Swift/BAT (GCN 27444). The Fermi GBM Final
Real-time Localization (GCN 27434) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 107
degrees.


The GBM light curve consists of a single peak with a duration (T90) of
about 1 s (50-300 keV). The time-averaged spectrum from T0-0.1 s to T0+1.2
s is
best fit by a power law function with an exponential high-energy cutoff.
The power law index is -0.64 +/- 0.11 and the cutoff energy, parameterized
as Epeak, is 913 +/- 192 keV.

The event fluence (10-1000 keV) in this time interval is  (2.49 +/-
0.12)E-6 erg/cm^2. The 64 ms peak photon flux measured starting from T0 +
256 ms in the 10-1000 keV band is 9.6 +/- 1.5 ph/s/cm^2.



The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support
Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"