GCN Circular 27226
Subject
Konus-Wind observation of GRB 200219A
Event
Date
2020-02-26T16:09:54Z (6 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:
The short-duration GRB 200219A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27123;
Bissaldi and Meegan, GCN Circ. 27137;
Swift-BAT detection: Lien et al., GCN Circ. 27125;
Laha et al., GCN Circ. 27148)
triggered Konus-Wind at T0=27405.513 s UT (07:36:45.513).
The burst light curve shows a single multi-peaked pulse
which starts at ~T0-0.2 s and has a total duration of ~0.4 s.
The emission is seen up to ~8 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200219_T27405/
As observed by Konus-Wind, the burst
had a fluence of 4.12(-0.61,+0.67)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.182 s,
of 2.34(-0.73,+0.76)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+0.256 s)
is best fit in the 20 keV - 8 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.06(-0.28,+0.35)
and Ep = 952(-173,+218) keV (chi2 = 29/27 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.6
(chi2 = 29/26 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.