GCN Circular 26149
Subject
Konus-Wind observation of GRB 191031D: correction to GCN 26126
Event
Date
2019-11-03T11:15:05Z (6 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, on behalf of the Konus-Wind team:
Reported in Frederiks et al. 2019 (GCN Circ. 26126),
the KW spectral parameters and fluxes of short/hard GRB 191031D
are incorrect due to wrong instrument calibrations used.
The correct values are given below.
As observed by Konus-Wind, the burst had a fluence
of 5.72(-0.63,+0.69)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.016 s,
of 4.12(-0.72,+0.80)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+0.256 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.12(-0.18,+0.20)
and Ep = 735(-92,+112) keV (chi2 = 32/39 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.9
(chi2 =32/38 dof).
I apologize for possible inconvenience this may have caused.