GCN Circular 38441
Subject
GRB 241204A: Fermi GBM Observation
Date
2024-12-04T21:07:30Z (a month ago)
From
Matt Godwin <msg0028@uah.edu>
Via
Web form
Matt Godwin (UAH), E. Bissaldi (Politecnico and INFN Bari), and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 03:39:22.51 UT on 04 December 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241204A (trigger 754976367/241204152).
which was also detected by Fermi-LAT (E. Bissaldi et al. 2024, GCN 38436).
The Fermi GBM on-ground location is consistent with the Fermi-LAT position.
The angle from the Fermi LAT boresight is 26 degrees.
The GBM light curve consists of two peaks with a duration (T90)
of about 0.8 s (50-300 keV). The time-averaged spectrum
from T0-0.4 to T0+1.0 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.31 +/- 0.04 and the cutoff energy,
parameterized as Epeak, is 3453 +/- 1070 keV.
The event fluence (10-1000 keV) in this time interval is
(2.22 +/- 0.09)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.64 s in the 10-1000 keV band is 41 +/- 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/"