[vsnet-grb-info 28517] GRB 210807C: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30620
SUBJECT: GRB 210807C: Fermi GBM detection
DATE:    21/08/08 22:58:37 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 22:55:24.31 UT on 7 July 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 210807C (trigger 650069729 / 210807955)
which was also detected by the Swift/BAT (Lien et al. 2021, GCN 30610).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 61
degrees.

The GBM light curve consists of multiple peaks followed by some
extended emission with a duration (T90) of about 125 s (50-300 keV).
The time-averaged spectrum from T0 s to T0+94.2 s
is best fit by a Band function, with Epeak = 170 +/- 28 keV,
alpha = -1.08 +/- 0.06  and beta = -1.61 +/- 0.01.

The event fluence (10-1000 keV) in this time interval is
(56.43 +/- 0.54)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+8.64 s in the 10-1000 keV band
is 7.2 +/- 0.3 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/"