GCN Circular 32033
Subject
Konus-Wind detection of GRB 220511A
Date
2022-05-13T13:04:48Z (2 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 220511A (AGILE detection: Ursi et al., GCN 32021;
AstroSat CZTI detection: Gopalakrishnan et al., GCN 32028;
Fermi-GBM observation: Veres & Meegan, GCN 32030)
triggered Konus-Wind (KW) at T0=49319.624 s UT (13:41:59.624).
The burst light curve shows a single emission pulse,
which starts at ~T0-1 s and has a total duration of ~6 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220511_T49319/
As observed by Konus-Wind, the burst had
a fluence of (7.8 �� 1.5)x10^-6 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 0.832 s,
of (4.2 �� 0.7)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 1.5 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.75 (-0.19,+0.42),
the high energy photon index beta = -3.1 (-6.9,+0.8),
the peak energy Ep = 159 (-34,+21) keV,
chi2 = 57/59 dof.
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.