GCN Circular 13103

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

The short very intense GRB 120323A
(Fermi/GBM detection: Gruber & Connaughton, GCN 13099
Not found
 
 
;
IPN localization: Golenetskii at al., GCN 13102
Not found
 
 
)
triggered Konus-Wind at T0=43815.970s UT (12:10:15.970)

The light curve shows a double-headed FRED-like structure.
A total duration of the burst is ~0.5 s.
The emission is seen up to ~8 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB120323_T43815/

A spectral lag between hard G3(300-1400 keV) and soft G1(22-80 keV)
instrument's light curves is estimated to (-0.002 +/- 0.004) s.

As observed by Konus-Wind the burst
had a fluence of 1.03(-0.07,+0.07)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.016 s,
of 7.2(-0.9,+0.9)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst
(measured from T0 to T0+0.256 s)
is well fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -1.57 (-0.07, +0.07),
and Ep = 331(-50, +64) keV,
chi2 = 45.8/42 dof.
Fitting this spectrum with the GRB (Band) function
gives an equally good result with the following model parameters:
the low-energy photon index alpha = -1.56 (-0.07, +0.09),
the high energy photon index beta = -2.9 (<-2.4),
the peak energy Ep = 317(-76, +68) keV,
chi2 = 44.3/41 dof.

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