TITLE:   GCN CIRCULAR
NUMBER:  32382
SUBJECT: Konus-Wind detection of GRB 220711C
DATE:    22/07/13 14:24:59 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The short-duration GRB 220711C
(IPN triangulation: Svinkin et al., GCN Circ 32373)
triggered Konus-Wind at T0=58317.557 s UT (16:11:57.557).

The burst light curve shows a single emission pulse,
which starts at T0-0.3 s and has a total duration of ~0.4 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/GRB220711_T58317/

As observed by Konus-Wind, the burst
had a fluence of 2.01(-0.37,+0.43)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.066 s,
of 1.27(-0.49,+0.52)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+0.128 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.06(-0.41,+0.55)
and Ep = 736(-169,+251) keV (chi2 = 19/26 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.0
(chi2 = 19/25 dof).

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