GCN Circular 38257
Subject
GRB 241115C: Fermi GBM Observation
Date
2024-11-16T21:50:57Z (16 days ago)
From
Lorenzo Scotton at UAH <lscottongcn@outlook.com>
Via
Web form
L. Scotton (UAH), S. Dalessi (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 04:35:33.96 UT on 15 November 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241115C (trigger 753338138/241115191).
which was also detected by Swift/BAT-GUANO (S. Ronchini et al. 2024, GCN 38245).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 257.26, Dec = 16.20 (J2000 degrees, equivalent to J2000 17h 9m, +16d 11'),
with a statistical uncertainty of 4.91 degrees. The Fermi GBM on-ground location
is consistent with the Swift/BAT-NITRATES position.
The angle from the Fermi LAT boresight is 66 degrees.
The GBM light curve consists of a single emission episode with a duration (T90)
of about 5.1 s (50-300 keV). The time-averaged spectrum
from T0-1.0 to T0+7.0 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.77 +/- 0.08 and the cutoff energy,
parameterized as Epeak, is 53 +/- 7 keV.
The event fluence (10-1000 keV) in this time interval is
(2.1 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.32 s in the 10-1000 keV band is 9.9 +/- 0.4 ph/s/cm^2.
A Band function fits the spectrum equally well with
Epeak = 51 +/- 7 keV, alpha = -1.72 +/- 0.11 and beta = -2.61 +/- 0.49.
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/"