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GCN Circular 34162

GRB 230707A: Fermi GBM Detection
2023-07-07T17:52:03Z (a year ago)
Peter Veres at University of Alabama in Huntsville <>
P. Veres and C. Meegan (both UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 03:22:51.96 UT on 07 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230707A (trigger 710392976/230707141),
which was also detected by the Swift/BAT-GUANO (Tohuvavohu et al.
2023, GCN 34159).
The Fermi GBM Final Real-time Localization (GCN 34156) is consistent
with the Swift position.
The angle from the Fermi LAT boresight is 63 degrees.

The GBM light curve consists of multiple pulses with a duration (T90)
of about 29 s (50-300 keV). The time-averaged spectrum
from T0-2.8 to T0+30.0 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.77 +/- 0.08 and the cutoff energy,
parameterized as Epeak, is 121 +/- 7 keV.

The event fluence (10-1000 keV) in this time interval is
(6.9 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.5 s in the 10-1000 keV band is 6.5 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 110 +/- 10 keV, alpha = -0.7 +/- 0.1 and beta = -2.5 +/- 0.2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:"

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