TITLE:   GCN CIRCULAR
NUMBER:  32122
SUBJECT: Konus-Wind detection of GRB 220525A
DATE:    22/05/26 12:36:42 GMT
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 220525A (Fermi GBM detection: Fermi GBM Team, GCN 32112;
BALROG localization: Kunzweiler et al., GCN 32113;
IPN triangulation: Kozyrev et al., GCN 32118)
triggered Konus-Wind (KW) at T0=654.268 s UT (00:10:54.268).

The burst light curve shows a single multipeaked pulse,
which starts at ~T0-3 s and has a total duration of ~12 s.
The emission is seen up to ~4 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220525_T00654/

As observed by Konus-Wind, the burst had
a fluence of (1.7 ± 0.3)x10^-6 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 2.624 s,
of (4.3 ± 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 - 15 MeV range by
a Band function with the following model parameters:
the low-energy photon index alpha = -0.69 (-0.22,+0.26),
the high energy photon index beta = -3.0 (-7.0,+0.44),
the peak energy Ep = 190 (-22,+26) keV,
chi2 = 88/96 dof.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.