GCN Circular 37301
Subject
GRB 240825A: Fermi GBM Observation
Event
Date
2024-08-26T16:12:52Z (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 15:53:00 UT on 25 August 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240825A (trigger 746293985/240825662),
which was also detected Swift (R. Gupta et al. 2024, GCN 37274),
Fermi-LAT (N. Di Lalla et al. 2024, GCN 37288), and
VLT/X-shooter (A. Martin-Carrillo et al. 2024, GCN 37293).
The Final Real-time Localization (Fermi GBM Team 2024, GCN 37273)
is consistent with Swift and Fermi-LAT.
The angle from the Fermi LAT boresight is 52 degrees.
The GBM light curve many overlapping short pulses with a
duration (T90) of about 4 s (50-300 keV). The time-averaged
spectrum from T0+0.96 to T0+6.85 s best fit by a Band function
with Epeak = 442 +/- 8 keV, alpha = -0.82 +/- 0.01,
and beta = -2.22 +/- 0.02.
The event fluence (10-1000 keV) in this time interval is
(1.01 +/- 0.01)E-04 erg/cm^2. The 1-s peak photon flux measured
starting from T0+1.22 s in the 10-1000 keV band is 203 +/- 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/"