GCN Circular 32901

Subject

Konus-Wind detection of GRB 221022C

Event

Date

2022-10-31T14:54:50Z (3 years ago)

From

Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The short-duration GRB 221022C
(IPN triangulation: Svinkin et al., GCN Circ. 32857Loading...
 
 )
triggered Konus-Wind at T0=52903.608 s UT (14:41:43.608).

The burst light curve shows a multipeaked structure,
which starts at T0-88 ms and has a total duration of ~128 ms.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB221022_T52903/

As observed by Konus-Wind, the burst
had a fluence of 8.55(-1.23,+1.68)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0-0.012 s,
of 2.01(-0.39,+0.47)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the main fraction of the burst emission was detected
before the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modelling the KW 3-channel time-integrated spectrum
(measured from T0-0.088 s to T0+0.040 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -0.09(-0.28,+0.40) and Ep = 548(-86,+121) keV.

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.