[vsnet-grb-info 21879] GRB 1903020A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23978
SUBJECT: GRB 1903020A: Fermi GBM observation
DATE:    19/03/20 09:00:55 GMT
FROM:    Andreas von Kienlin at MPE  <azk at mpe.mpg.de>

A. von Kienlin (MPE), S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:

"At 01:14:16.49 UT on 20 March 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 1903020A (trigger 574737261 / 190320052),
which was also detected by the Swift/BAT (Gropp et al. 2008, GCN 23973).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 59.7 degrees.

The GBM light curve shows a structured pulse with a 
duration (T90) of about 43 s (50-300 keV).
The time-averaged spectrum from T0-4.096 s to T0+32.769 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.75 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 314 +/- 35 keV

The event fluence (10-1000 keV) in this time interval is
(6.7 +/- 0.4)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+29.44 s in the 10-1000 keV band
is 1.93 +/- 0.17 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 296 +/- 51 keV, alpha = -0.74 +/- 0.09 and beta = -2.2 +/- 0.4. 

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."