GCN Circular 34381
Subject
GRB 230808A: Fermi GBM Detection
Date
2023-08-11T15:01:08Z (9 months ago)
From
Ava Myers at NASA GSFC <ava.myers@nasa.gov>
Via
Web form
A. Myers (NPP/GSFC) and S. Lesage (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
“At 10:49:12.78 UT on 08 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230808A (trigger 713184557/230808451, which was also detected by Swift/BAT-GUANO (B. Person et al. 2020; GCN 34375 reported by James Delaunay). The Fermi GBM Final Real-time Localization was reported at GCN 34369.
The angle from the Fermi LAT boresight is 36 degrees.
The GBM light curve consists of a multiple-emission episode with a duration (T90) of about 62 s (50-300 keV). The time-averaged spectrum from T0-4.6 to T0+69.1 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.07 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 430 +/- 60 keV.
The event fluence (10-1000 keV) in this time interval is (1.31 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+18 s in the 10-1000 keV band is 6.4 +/- 0.3 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/"