[vsnet-grb-info 15579] Konus-Wind observation of GRB 140930B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16868
SUBJECT: Konus-Wind observation of GRB 140930B
DATE:    14/10/01 13:06:20 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, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

A short-duration, hard-spectrum GRB 140930B (Swift-BAT detection: 
Pasquale et al., GCN 16857) triggered Konus-Wind at T0=70907.149 s UT 
(19:41:47.149).

The burst light curve shows a single pulse with a duration of ~1.0 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140930_T70907/

As observed by Konus-Wind, the burst
had a fluence of 8.1(-2.5,+5.1)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.010 s,
of 3.4(-1.1,+2.3)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.6 (-0.5,+0.6)
and Ep = 1302 (-459,+2009) keV (chi2 = 99/92 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -1.6
(chi2 = 98/91 dof)

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