GCN Circular 32994
Subject
GRB 221126A: Fermi GBM observation
Event
Date
2022-11-29T11:59:03Z (3 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE) and C. Meegan (UAH) report on behalf of the Fermi GBM
Team:
"At 13:07:29.94 UT on 26 November 2022, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 221126A (trigger 691160854 / 221126547).
This event was also observed by Swift/BAT-GUANO (GCN 32987), AstroSat CZTI
(GCN 32990)
and AGILE (GCN 32992).
The GBM position is reported in the Fermi-GBM Final on-ground Localization
(GCN 32985).
The angle from the Fermi LAT boresight is 22 degrees.
The GBM light curve shows a structured pulse with a duration (T90) of about
7 s (50-300 keV).
The time-averaged spectrum from T0-0.90 s to T0+8.32 s is best fit by a
power law function
with an exponential high-energy cutoff. The power law index is -0.94 +/-
0.03 and the cutoff energy,
parameterized as Epeak, is 194 +/- 8 keV
The event fluence (10-1000 keV) in this time interval is (9.29 +/- 0.02)E-06
erg/cm^2. The 1.024-sec
peak photon flux measured starting from T0+4.224 s in the 10-1000 keV band
is 15.7 +/- 0.4 ph/s/cm^2.
A Band function fits the spectrum equally well with Epeak= 190 +/- 10 keV,
alpha = -0.92 +/- 0.04
and beta = -3.1 +/- 0.6.
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/"