GCN Circular 38456
Subject
GRB 241206A: Fermi GBM observation
Date
2024-12-07T11:45:13Z (a month ago)
From
Christian Malacaria at INAF-OAR <cmalacaria.astro@gmail.com>
Via
Web form
C. Malacaria (INAF-OAR) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 12:06:49.88 UT on 06 December 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241206A (trigger 755179614/241206505).
The Fermi GBM Final Real-time Localization is reported in GCN 38447.
Swift-BAT/GUANO also detected the burst (GCN 38453, DeLaunay et al. 2024)
and its localization is consistent with the Fermi GBM localization.
The angle from the Fermi LAT boresight is 38 degrees.
The GBM light curve consists of a double peak with a duration (T90)
of about 31 s (50-300 keV). The time-averaged spectrum
from T0-1.9 to T0+16.5 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.5 +/- 0.1 and the cutoff energy,
parameterized as Epeak, is 87 +/- 12 keV.
The event fluence (10-1000 keV) in this time interval is
(2.4 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+21 s in the 10-1000 keV band is 6.0 +/- 0.3 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 70 +/- 20 keV, alpha = -1.4 +/- 0.2 and beta = -2.3 +/- 0.3.
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/"