GCN Circular 24083
Subject
Konus-Wind observation of GRB 190404B
Date
2019-04-09T16:28:57Z (5 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@mail.ioffe.ru>
A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:
The long GRB 190404B which triggered MAXI/GSC at 12:24:20 UT
(MAXI/GSC detection: Nakajima et al., GCN 24048;
CALET Gamma-Ray Burst Monitor detection: Nakahira et al., GCN 24055)
was detected by Konus-Wind in the waiting mode.
The burst light curve shows a single multi-peaked emission episode
started at ~T0(MAXI)-7.4 s with a total�� duration of ~85.4 s.
As observed by Konus-Wind, the burst had a fluence of
5.57(-1.00,+1.34)x10^-6 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(MAXI)+51.5 s, of 1.09(-0.20,+0.26)x10^-7 erg/cm2/s
(both in the 20 - 1200 keV energy range).
Fitting the K-W 3-channel time-integrated spectrum
(from ~T0(MAXI)-7.4 s to ~T0(MAXI)+78.0 s) in the 20 keV - 1.2 MeV range
by a power law with exponential cutoff model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields
alpha = -1.64(-0.36,+3.80),
and Ep =80(-39,+33) keV.
All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB190404B/