Konus-Wind detection of GRB 220609B
Abstract
The long GRB 220609B (CALET-CGBM detection: Asaoka et al., GCN Circ 32185; AstroSat-CZTI detection: Gopalakrishnan et al., GCN Circ 32186; IPN localization: Kozyrev et al., GCN 32190) triggered Konus-Wind (KW) at T0=44473.865 s UT (12:21:13.865). The burst light curve shows a single emission pulse which starts at ~T0-1.5 s and has a total duration of ~18 s. The emission is seen up to ~10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB220609_T44473/ As observed by Konus-Wind, the burst had a fluence of (1.0 ± 0.1)x10^-4 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 4.544 s, of (2.7 ± 0.2)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+14.592 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 = -0.79 (-0.11,+0.13), the high energy photon index beta = -2.02 (-0.14,+0.10), the peak energy Ep = 537 (-86,+112) keV, chi2 = 113/98 dof. The spectrum near the peak count rate (measured from T0 to T0+6.400 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 = -0.83 (-0.06,+0.07), the high energy photon index beta = -2.04 (-0.17,+0.12), the peak energy Ep = 748 (-145,+170) keV, chi2 = 88/97 dof. All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- June 2022
- Bibcode:
- 2022GCN.32250....1F