[vsnet-grb-info 19761] Konus-Wind observation of GRB 170827B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21775
SUBJECT: Konus-Wind observation of GRB 170827B
DATE:    17/08/31 14:13:20 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

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

The short-duration GRB 170827B
(IPN Triangulation: Svinkin et al., GCN Circ. 21735)
triggered Konus-Wind at T0=70686.844 s UT (19:38:06.844).

The burst light curve shows a single pulse which starts
at ~T0-0.150 s and has a total duration of ~0.180 s.

As observed by Konus-Wind, the burst
had a fluence of 4.2(-0.8,+1.1)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0+0.018 s,
of 3.8(-1.3,+1.5)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Modeling the KW 3-channel time-integrated spectrum
(from T0-0.148 s to T0+0.032 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.21(-0.34,+0.56) and Ep = 345(-79,+121) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170827_T70686/

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.