[vsnet-grb-info 16714] Konus-Wind observation of GRB 150702A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17995
SUBJECT: Konus-Wind observation of GRB 150702A
DATE:    15/07/06 16:56:21 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova 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:

The long-duration, hard-spectrum GRB 150702A
(Fermi-LAT detection: Vianello, Monzani & Axelsson, GCN 17989;
IPN triangulation: Hurley et al., GCN 17993;
Fermi GBM detection: Jenke, GCN 17994)
triggered Konus-Wind at T0=86198.645 s UT (23:56:38.645).

The burst light curve starts, at ~T0-0.5 s, with a double-peaked pulse
which is followed by the weaker flaring which extends till ~T0+70 s.
The emission is seen up to ~18 MeV.

As observed by Konus-Wind, the burst
had a fluence of 5.50(-1.45,+1.86)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+1.200 s,
of 1.75(-0.61,+0.70)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+65.984 s)
is best fit in the 20 keV - 18 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.24(-0.09,+0.11),
and Ep = 2059(-903,+1940) keV (chi2 = 106/98 dof).

The spectrum near the peak count rate
(measured from T0 to T0+8.640 s)
is best fit in the 20 keV - 18 MeV range
by the power law with exponential cutoff model:
with  alpha = -1.11(-0.11,+0.14),
and Ep = 2310(-1007,+2032) keV (chi2 = 103/97 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB150702_T86198/

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