GCN Circular 34358

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 230803A (Fermi GBM detection: Fermi GBM team, GCN 34325
Not found
 
 
;
AstroSat CZTI detection: Navaneeth et al., GCN 34328
Not found
 
 
;
IPN triangulation: Kozyrev et al., GCN 34330
Not found
 
 
)
triggered Konus-Wind (KW) at T0=5229.064 s UT (01:27:09.064).

The burst light curve shows a multi-peaked structure
with a total duration of ~126 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB230803_T05229/

As observed by Konus-Wind, the burst had
a fluence of (7.59 ± 0.88)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 93.760 s,
of (1.43 ± 0.13)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0+57.600 to T0+128.256 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.30 (-0.06,+0.08),
the high energy photon index beta = -2.65 (-0.82,+0.30),
the peak energy Ep = 256 (-31,+32) keV,
chi2 = 112/97 dof.

The spectrum near the peak count rate (measured from T0+90.368 to T0+95.488 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.93 (-0.06,+0.07),
the high energy photon index beta = -2.32 (-0.20,+0.14),
the peak energy Ep = 284 (-38,+40) keV,
chi2 = 66/77 dof.

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