[vsnet-grb-info 16159] Konus-Wind observation of GRB 150210A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17440
SUBJECT: Konus-Wind observation of GRB 150210A
DATE:    15/02/11 15:04:47 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, hard-spectrum GRB 150210A
(Fermi-GBM detection: Burns, GCN 17432;
Fermi-LAT detection: Zhu et al., GCN 17438;
IPN triangulation: Golenetskii et al., GCN 17439)
triggered Konus-Wind at T0=80787.209 s UT (22:26:27.209).

The light curve shows a bright, multi-peaked pulse with a duration
of ~3.5 s followed by a much weaker tail visible up to ~T0+30 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/GRB150210_T80787/

As observed by Konus-Wind, the burst had a fluence
of 7.8(-0.8,+0.9)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0+2.368 s, of 4.2(-0.3,+0.3)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+24.832 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.99(-0.07,+0.08),
and the peak energy Ep = 2170(-340,+440) keV,
chi2 = 107/98 dof.
Fitting this spectrum with the Band model yields the same
values of alpha and Ep with an upper limit on the high-energy
photon index beta of -2.6

The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.89(-0.06,+0.06),
and the peak energy Ep = 2250(-240,+280) keV,
chi2 = 126/98 dof.

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