GCN Circular 37284
Subject
GRB 240824B: Fermi GBM Observation
Event
Date
2024-08-25T20:38:41Z (2 years ago)
From
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov>
Via
Web form
V. Sharma (NASA GSFC/UMBC), and C. Meegan (UAH) report on behalf of the
Fermi Gamma-ray Burst Monitor Team:
At 13:11:16.70 UT on 24 August 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240824B (trigger 746197881/240824549), which was
also detected by MAXI/GSC detection (M. Nakajima et al., 2024, GCN 37261),
Swift-BAT (J. DeLaunay et al. 2024, GCN 37267), and Swift-XRT (A. Tohuvavohu
et al. 2024, GCN 37269 and J.A. Kennea et al. 2024, GCN 37270).
The Final Real-time Localization (Fermi GBM Team 2024, GCN 37260)
is consistent with the MAXI/GSC, and Swift.
The angle from the Fermi LAT boresight is 79 degrees.
The GBM light curve many short peaks with a duration (T90)
of about 1.5 s (50-300 keV). The time-averaged spectrum
from T0-0.96 to T0+0.90 s is best fit by a power law
function with an exponential high-energy cutoff.
The power law index is -0.83 +/- 0.38 and the cutoff energy,
parameterized as Epeak, is 339 +/- 200 keV.
The event fluence (10-1000 keV) in this time interval is
(4 +/- 1)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.64 s in the 10-1000 keV band is 3 +/- 1 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/"