[vsnet-grb-info 24851] Konus-Wind observation of GRB 200130B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26950
SUBJECT: Konus-Wind observation of GRB 200130B
DATE:    20/01/31 16:08:04 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

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

The long-duration GRB 200130B
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 26944;
BALROG localization: Kunzweiler et al., GCN Circ. 26945;
IPN triangulation: Hurley et al., GCN Circ. 26949)
triggered Konus-Wind at T0=35999.282 s UT (09:59:59.282).

The burst light curve shows an initial intense pulse
which starts at ~T0-0.3 s followed by a weaker emission up to ~12 s.
The emission is seen up to ~1 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200130_T35999/

As observed by Konus-Wind, the burst
had a fluence of 1.10(-0.09,+0.11)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.284 s,
of 6.59(-1.21,+1.34)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+16.640 s)
is best fit in the 20 keV - 1 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.88(-0.19,+0.24),
the high energy photon index beta = -3.58(-6.42,+0.64),
the peak energy Ep = 90(-6,+6) keV
(chi2 = 55/44 dof).

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+8.448 s)
is best fit in the 20 keV - 1 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.85(-0.20,+0.26),
the high energy photon index beta = -4.01(-5.99,+0.98),
the peak energy Ep = 91(-6,+6) keV
(chi2 = 44/44 dof).

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