GCN Circular 37478
Subject
GRB 240912A: Fermi GBM Observation
Event
Date
2024-09-12T18:37:53Z (a year ago)
From
Jacob Smith at Fermi-GBM Team <jrs0118@uah.edu>
Via
Web form
J. Smith (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 01:46:40.59 UT on 12 September 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240912A (trigger 747798405/240912074).
which was also detected by Swift BAT and XRT (P. A. Evans et al. 2024, GCN 37466), INTEGRAL SPI ACS (D. Pawar 2024, GCN 37473), OSIRIS+/GTC (A. de Ugarte Postigo et al. 2024, GCN 37469), and NOT (J. An et al. 2024, GCN 37471).
The Fermi GBM on-ground location is consistent with the Swift BAT/XRT position.
The angle from the Fermi LAT boresight is 71 degrees.
The GBM light curve single emission episode with a duration (T90)
of about 88.6 s (50-300 keV). The time-averaged spectrum
from T0+0 to T0+124.930 s is best fit by
a Band function
with Epeak = 147 +/- 7 keV, alpha = -1.31 +/- 0.02,
and beta = -2.21 +/- 0.05.
The event fluence (10-1000 keV) in this time interval is
(8.953 +/- 0.089)E-05 erg/cm^2. The 1.024-s peak photon flux measured
starting from T0+60.2 s in the 10-1000 keV band is 26.43 +/- 0.4 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/"