[vsnet-grb-info 14767] GRB 140406A: Fermi GBM observation

GCN Circulars gcncirc at capella2.gsfc.nasa.gov
Sun Apr 6 23:14:23 JST 2014


TITLE:   GCN CIRCULAR
NUMBER:  16081
SUBJECT: GRB 140406A: Fermi GBM observation
DATE:    14/04/06 14:14:15 GMT
FROM:    Hoi-Fung Yu at MPE  <sptfung at mpe.mpg.de>

Subject: GRB 140406A: Fermi GBM observation

Hoi-Fung Yu (MPE) reports on behalf of the Fermi GBM Team:

"At 03:26:48.19 UT on 06 April 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140406A (trigger 418447611 / 140406144).
This burst, tentatively classified as Unreliable Location by the FSW,
is in fact due to Gamma-Ray Burst.

The on-ground calculated location, using the GBM trigger data, is
RA = 70.1, Dec = 13.5 (J2000 degrees, equivalent to 04h 40m, 13d 30'),
with an uncertainty of 6 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 58 degrees.

The GBM light curve consists of several pulses with a duration (T90)
of about 42 s (50-300 keV). The time-averaged spectrum from T0-4.096 s
to T0+36.864 s is well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.3 +/- 0.2 and the cutoff
energy, parameterized as Epeak, is 138 +/- 13 keV.

The event fluence (10-1000 keV) in this time interval is
(2.8 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+30.8 s in the 10-1000 keV band is 1.5 +/- 0.2 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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