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GCN Circular 16790

GRB 140906B: Fermi GBM Detection of a Long GRB
2014-09-07T19:18:41Z (10 years ago)
Oliver Roberts at UCD/Fermi <>
O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team:

"At 10:18:02.36 UT on the 6th of September 2014, the Fermi Gamma-Ray
Burst Monitor triggered and located GRB 140906B
(trigger 431691485/140906429). The trigger resulted in an Autonomous
Repoint Request (ARR) that was accepted. The GBM on-ground location
is consistent with the Fermi flight software position.

The on-ground calculated location, using the GBM trigger data, is
RA = 187.09, DEC = +1.02 (J2000 degrees, equivalent to
 +16h 33m, +49d 30'), with an uncertainty of 2 degrees (radius,
1-sigma containment, statistical only; there is additionally a
systematic error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 47 degrees.

The GBM light curve consists of several bright emission episodes,
with a duration (T90) of about 23 seconds (50-300 keV). The
time-averaged spectrum from T0+0 s to T0+23 s is well fit by a
power law function with an exponential high-energy cutoff. The power
law index is -1.4 +/- 0.1 and the cutoff energy, parameterized as
Epeak, is 330 +/- 48 keV.

The event fluence (10-1000 keV) in this time interval is
(9.91 +/- 0.07)E-06 erg/cm^2. The 1.024-sec peak photon flux
measured starting from T0+15 s in the 10-1000 keV band is
11.0+/-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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