[vsnet-grb-info 12719] GRB 121211A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14078
SUBJECT: GRB 121211A: Fermi GBM observation
DATE:    12/12/13 09:02:10 GMT
FROM:    Hoi-Fung Yu at MPE  <sptfung at mpe.mpg.de>

David Yu (MPE) reports on behalf of the Fermi GBM Team:

"At 13:47:03.59 UT on 11 December 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 121211A (trigger 376926426 / 121211574)
which was also detected by the Swift/BAT (Mangano et al. 2012, GCN 14057).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 74 degrees.

The GBM light curve consists of a double peaked pulse
with a duration (T90) of about 5.4 s (50-300 keV).
The time-averaged spectrum from T0-3.072 s to T0+1.536 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.30 +/- 0.34 and
the cutoff energy, parameterized as Epeak, is 95.96 +/- 12.60 keV.

The event fluence (10-1000 keV) in this time interval is
(4.825 +/- 0.507)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.768 s in the 10-1000 keV band
is 2.402 +/- 0.202 ph/s/cm^2.

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