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GCN Circular 13773

GRB 120913B: Fermi GBM observation
2012-09-15T02:44:26Z (12 years ago)
Veronique Pelassa at UAH <>
V. Pelassa (UAH) reports on behalf of the Fermi GBM Team:

"At 23:55:58.77 UT on 13 september 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 120913B (trigger 369273361 / 120913997), which
was also detected by the Swift/BAT (E.A. Helder et al. 2008, GCN 13763)
The GBM on-ground location is consistent with the Swift position.
 The angle from the Fermi LAT boresight is 66 degrees.

The GBM light curve consists of 2 peaks at T0-10 and T0+30s on top of a
longer plateau, with a duration (T90) of about 110 s (50-300 keV).
The time-averaged spectrum from T0-40.961 s to T0+98.306 s is
best fit by a Band function with Epeak = 163 +/- 23 keV,
alpha = -1.19 +/- 0.06, and beta = -1.97 +/- 0.07
(Cstat 604 for 483 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(2.9 +/- 0.7)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+37.632 s in the 10-1000 keV band
is 5.0 +/- 0.3 ph/s/cm^2.

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