[vsnet-grb-info 24538] Konus-Wind observation of GRB200101A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26637
SUBJECT: Konus-Wind observation of GRB200101A
DATE:    20/01/05 21:44:21 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova at mail.ioffe.ru>

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

The long-duration, hard-spectrum, very bright GRB200101A
(Fermi GBM detection: Veres & Meegan, GCN 26627;
AstroSat CZTI detection: Gaikwad et al., GCN 26632;
IPN triangulation: Hurley et al., GCN 26635)
triggered Konus-Wind at T0=74367.095 s UT (20:39:27.095).

The burst light curve shows a a double-peaked structure
which starts at ~T0-8.3 s and has a total duration of~81.8 s
The emission is seen up to ~20 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.43(-0.09,+0.09)x10^-4 erg/cm2,
and a 64-ms peak energy flux, measured from T0+7.776 s,
of 1.12(-0.12,+0.12)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+17.408 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.74(-0.06,+0.07),
the high energy photon index beta = -2.45(-0.23,+0.16),
the peak energy Ep = 552(-46,+49) keV,
chi2 = 103/97 dof.

The spectrum near the peak count rate
(measured from T0+7.680 to T0+7.936 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.43(-0.15,+0.18),
the high energy photon index beta = -2.06(-0.15,+0.11),
the peak energy Ep = 610(-105,+124) keV,
chi2 = 50/55 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200101_T74367/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.