[vsnet-grb-info 28138] GRB 210323B: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30241
SUBJECT: GRB 210323B: Fermi GBM observation
DATE:    21/06/16 17:23:38 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi at ba.infn.it>

E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:


"At 12:03:33.09 UT on 23 March 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 210323B (trigger 638193818/ 210323502),
which was also detected by the Swift/BAT-GUANO (DeLaunay et al. 2021, GCN 29701).
The Fermi GBM Final Real-time Localization is consistent with the Swift position.

The angle from the Fermi LAT boresight
at the GBM trigger time is 10 degrees.

The GBM light curve consists of a weak emission episode
with a duration (T90) of about 14 s (50-300 keV).
The time-averaged spectrum from T0-4.9 s to T0+5.9 s is
adequately fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.94 +/- 0.26 and
the cutoff energy, parameterized as Epeak, is 740 +/- 540 keV.

The event fluence (10-1000 keV) in this time interval is
(2.1 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-4.5 s in the 10-1000 keV band
is 1.1 +/- 0.2 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/"