TITLE: GCN CIRCULAR NUMBER: 32614 SUBJECT: Konus-Wind detection of GRB 220930A DATE: 22/10/02 17:09:27 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 long-duration GRB 220930A (Swift-BAT detection: Cenko et al., GCN 32603, Barthelmy et al., GCN 32612; AstroSat-CZTI detection: Gopalakrishnan et al., GCN 32613) triggered Konus-Wind at T0=40312.503 s UT (11:11:52.503).
The burst light curve shows a multipeaked structure which starts at ~T0-1.5 s and has a total duration of ~76.0 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/GRB220930_T40312/
As observed by Konus-Wind, the burst had a fluence of 1.78(-0.64,+0.98)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+0.960 s, of 5.39(-2.28,+2.15)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+73.984 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.06(-1.06,+1.43), the high energy photon index beta = -2.41(-0.51,+0.46), the peak energy Ep = 198(-58,+181) keV (chi2 = 91/98 dof).
The spectrum near the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.38(-0.56,+0.66), the high energy photon index beta = -2.25(-1.42,+0.23), the peak energy Ep = 215(-52,+121) keV (chi2 = 97/96 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.