[vsnet-grb-info 21933] GRB 190331A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24032
SUBJECT: GRB 190331A: Fermi GBM detection
DATE:    19/04/01 00:18:35 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076 at uah.edu>

S. Poolakkil (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 02:14:37.57 UT on 31 March 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190331A (trigger 575691282/ 190331093),
which was also detected by the Swift/BAT (Page et al. 2019, GCN 24027).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight
at the GBM trigger time is 40 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 4.8 s (50-300 keV).
The time-averaged spectrum from T0-1.0 s to T0+6.1 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.74 +/- 0.19 and
the cutoff energy, parameterized as Epeak, is 214 +/- 47 keV.

The event fluence (10-1000 keV) in this time interval is
(1.343 +/- 0.179)E-06 erg/cm^2. The 1-sec peak photon flux
measured starting from T-0.06 s in the 10-1000 keV band
is 4.6 +/- 0.2 ph/s/cm^2.

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