TITLE: GCN CIRCULAR NUMBER: 32901 SUBJECT: Konus-Wind detection of GRB 221022C DATE: 22/10/31 14:54:50 GMT 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. 32857) 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.