[vsnet-grb-info 12414] Konus-Wind observation of GRB 120919B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13789
SUBJECT: Konus-Wind observation of GRB 120919B
DATE:    12/09/20 15:52:27 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

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 long-duration, moderately intense GRB 120919B
(IPN detection and localization: Hurley et al., GCN 13788)
triggered Konus-Wind at T0=04499.597s UT (01:14:59.401)

The light curve shows multiple pulses in the time interval
starting at ~T0-30s and ending at ~T0+100s.
The emission in the main bursting episode is seen up to 8 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB120919_T04499/

As observed by Konus-Wind, the burst
had a fluence of 3.1(-0.5,+0.7)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+13.056 s,
of 4.3(-0.9,+1.1)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+98.560 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.9 (-0.4, +0.5),
the high energy photon index beta = -2.3 (-2.7, +0.3),
the peak energy Ep = 250(-60, +190) keV,
chi2 = 86.9/83 dof.

The spectrum of the main bursting episode (measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.0 (-0.2, +0.2),
the high energy photon index beta = -2.4 (-1.0, +0.3),
the peak energy Ep = 300(-70, +85) keV,
chi2 = 76.3/83 dof.

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