[vsnet-grb-info 10541] Konus-Wind observation of GRB 110422A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11971
SUBJECT: Konus-Wind observation of GRB 110422A
DATE:    11/04/24 09:30:07 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>

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

The long bright GRB 110422A (Swift-BAT trigger #451901: Mangano et al.,
GCN 11957; Palmer et al., GCN 11959) triggered Konus-Wind at
T0(KW)=56502.948 s UT (15:41:42.948).
The burst light curve shows a multipeaked structure with a
duration of ~40 s.

As observed by Konus-Wind the burst
had a fluence of (8.56 +/- 0.02)x10^-5 erg/cm2,
and a 64-ms peak flux measured from T0+18.128 s
of (1.20 +/- 0.15)x10^-5 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+38.656 s) can be fitted (in the 20 keV - 2 MeV
range) by the GRB (Band) model for which:
the low-energy photon index is alpha = -0.65 +/- 0.06,
the high energy photon index beta = -2.96(-0.19, +0.14),
the peak energy Ep = 152 +/- 5 keV (chi2 = 96.8/64 dof).
The spectrum at the maximum count rate
(measured from T0+17.664 to T0+18.432 s) is well fitted
(in the 20 keV - 2 MeV range) by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.53 (-0.14, +0.17),
the high energy photon index beta = -2.65 (-0.62, +0.28),
the peak energy Ep = 246(-34, +37) keV (chi2 = 55.7/48 dof).

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

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB110422_T56502/