GCN Circular 12135
Subject
Konus-Wind observation of GRB 110709B
Date
2011-07-10T10:56:50Z (13 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@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 GRB 110709B (Swift-BAT trigger #456967:
Cummings et al., GCN 12122; Barthelmy et al., GCN 12130)
triggered Konus-Wind at T0=77564.576s UT (21:32:44.576)
The burst light curve shows a multi-peaked
pulse with a total duration of ~70 s.
The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110709_T77564/
As observed by Konus-Wind the burst
had a fluence of (2.6 � 0.2)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+13.824 s,
of (1.1 � 0.1)x10-5 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+41.216 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.0 (-0.13, +0.14),
and Ep = 278(-32, +43) keV,
chi2 = 62.7/73 dof.
The spectrum at the maximum count rate
(measured from T0+8.448 to T0+16.640 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -0.56 (-0.26, +0.30),
and Ep = 231(-28, +38) keV,
chi2 = 65.9/73 dof.
The renewed source activity (Swift-BAT trigger #456969:
Barthelmy et al., GCN 12124) fell into the telemetry gap
but was recorded by the instrument's spare count
rate measurement channel. This low-resolution record
(in the 70-300 keV energy range) shows a double-pulsed
structure lasting for ~100 s from T0+573 s to T0+675 s
(21:42:17 - 21:43:59) and having slightly weaker intensity
as compared to the initial burst.
All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.