GCN Circular 33162
Subject
GRB 230111A: Fermi GBM Observation
Date
2023-01-12T17:54:28Z (2 years ago)
From
Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>
O.J. Roberts (USRA) and C. Meegan (UAH) report on
behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 19:07:42.90 UT on 11 January 2023, the Fermi
Gamma-ray Burst Monitor (GBM) triggered and located
GRB 230111A (trigger 695156867/230111797), which was
also detected by MAXI (K. Setoguchi et al. 2023, GCN 33157).
The Fermi GBM Localization reported in GCN 33156 is consistent
with the MAXI location.
The angle from the Fermi LAT boresight is 108 degrees.
The GBM light curve consists of a single peak with a duration (T90)
of about 9 s (50-300 keV). The time-averaged spectrum
from T0-3.6 to T0+4.8 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.31 +/- 0.30 and the cutoff energy,
parameterized as Epeak, is 122 +/- 16 keV.
The event fluence (10-1000 keV) in this time interval is
(1.16 +/- 0.12)E-06 erg/cm^2. The measured 1-s peak photon flux
starting from T0-0.9 s in the 10-1000 keV band is 2.6 +/- 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/"