[vsnet-grb-info 14663] GRB 140311C: Fermi GBM Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15977
SUBJECT: GRB 140311C: Fermi GBM Detection
DATE:    14/03/12 22:28:45 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001 at uah.edu>

M. Stanbro (UAH) reports on behalf of the Fermi GBM Team:

"At 14:49:13.10 UT on 11 March 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140311C (trigger 416242156/140311618).
iPTF reported an optical counterpart candidate for this
source (L.P. Singer et al. 2014, GCN 15971).

The GBM on-ground location, using the Fermi GBM trigger data,
is RA = 183.7 , DEC = +62.81 (J2000 degrees, equivalent to
12h 14m, 62d 48'), with an uncertainty of 3 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 to the Fermi LAT boresight is 53 deg.

The GBM light curve consists of single peak with a
duration (T90) of 14 s (50-300 keV).
The time-averaged spectrum from T0-2 s to T0+12 s is
well fit by a Band function parameterized as Epeak = 56 +/- 6 keV,
alpha = -0.9 +/- 0.16 and beta = -2.4 +/- 0.12.

The event fluence (10-1000 keV) in this time interval is
(4.6 +/- 0.2)E-06 erg/cm^2. The 1.0-sec peak photon flux measured
starting from T0+0.3 s in the 10-1000 keV band
is 10.7 +/- 0.4 ph/s/cm^2.

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