[vsnet-grb-info 14629] Konus-Wind observation of GRB 140308A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15943
SUBJECT: Konus-Wind observation of GRB 140308A
DATE:    14/03/10 20:15:26 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline on behalf
of the Konus-Wind team, report:

The bright long-duration hard-spectrum 140308A (IPN triangulation: 
Hurley et al., GCN 15941) triggered Konus-Wind at T0=13764.906 s UT 
(03:49:24.906).

The burst light curve shows a multi-peaked structure with a total 
duration of ~90 s. The emission is seen up to ~18 MeV.

As observed by Konus-Wind, the burst
had a fluence of (1.01 +/- 0.10)x10^-4 erg/cm2,
and a 256-ms peak flux, measured from T0+16.976 s,
of (8.7 +/- 1.6)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+65.024 s)
is best fit in the 26 keV - 18 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.81 (-0.15,+0.17),
the high energy photon index beta = -2.07 (-0.16,+0.11),
the peak energy Ep = 246 (-35, 45) keV,
chi2 = 109/97 dof.

The spectrum near the maximum count rate
(measured from T0+15.872 to T0+24.064 s)
is best fit in the 26 keV - 18 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.67 (-0.26,+0.29),
the high energy photon index beta = -2.06 (-0.26,+0.14),
the peak energy Ep = 228 (-43, 74) keV,
chi2 = 96/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140308_T13764/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.