[vsnet-grb-info 8174] Konus-Wind and Konus-RF observations of GRB 090719

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9704
SUBJECT: Konus-Wind and Konus-RF observations of GRB 090719
DATE:    09/07/24 12:11:25 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

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

The long GRB 090719 (Fermi/GBM trigger 269659888/090719063;
A.J. van der Horst, GCN 9691)
triggered Konus-Wind at T0=05489.199 s UT (01:31:29.199),
and Konus-RF instrument onboard CORONAS-PHOTON s/c
at T0=05487.876 s UT (01:31:27.876),

The burst light curve shows a smooth structure
with a duration of ~20 s. The Konus-RF and Konus-Wind
light curves of this GRB are available at
http://www.ioffe.ru/LEA/GRBs/GRB090719_T05489/
===========================================================

As observed by Konus-Wind the burst
had a fluence of (4.6 ± 0.1)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+4.992 s,
of 9.4(-0.5, +0.6)x10-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+16.128 s) is well fit
(in the 20 keV - 2 MeV range) by GRB (Band) model
for which:
the low-energy photon index alpha = -0.76 ± 0.05,
the high energy photon index beta = -4.7( < -3.3),
the peak energy Ep = 260(-11, +10) keV (chi2 = 50/48 dof).

The spectrum at the maximum count rate
(from T0+4.096 to T0+5.120 s) is well fit
(in the 20 keV - 2 MeV range) by GRB (Band) model
for which:
the low-energy photon index alpha = -0.44(-0.56,+0.31),
the high energy photon index beta = -3.7( < -2.8),
the peak energy Ep = 328(-31, +32) keV (chi2 = 50/48 dof).
===========================================================

As observed by Konus-RF the burst
had a fluence of 5.2(-0.15, +0.15)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+3.368s,
of 1.1(-0.1, +0.1)x10-5 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0-2.0 to T0+20.0 s) is well fit
(in the 20 keV - 2 MeV range) by GRB (Band) model
for which:
the low-energy photon index alpha = -0.85 ± 0.5,
the high energy photon index beta = -3.7( < -3.0),
the peak energy Ep = 286(-15, +15) keV (chi2 = 141/130 dof).

The spectrum at the maximum count rate
(from T0+3.0 to T0+3.5 s) is well fit
(in the 20 keV - 2 MeV range) by GRB (Band) model
for which:
the low-energy photon index alpha = -0.26(-0.19,+0.28),
the high energy photon index beta = -2.9( < -2.3),
the peak energy Ep = 327(-60, +60) keV (chi2 = 73/70 dof).
===========================================================

Due to uncertainties in the burst incident angles
the quoted values are preliminary.
All the quoted errors are at the 90% confidence level.
--