GCN Circular 14720
Subject
Konus-Wind observation of GRB 130527A
Date
2013-05-29T14:11:48Z (11 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long-duration intense hard-spectrum GRB 130527A
(Swift-BAT trigger 556753: Gompertz et al., GCN 14703;)
Baumgartner et al., GCN 14708)
triggered Konus-Wind at T0=51688.300s UT (14:21:28.300).
The light curve shows a bright hard multi-peaked
emission complex from ~T0 s to ~T0+10s,
followed by the weaker and softer emission out to ~T0+40s.
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/GRB130527_T51688/
As observed by Konus-Wind, the burst
had a fluence of (1.1 � 0.05)x10-4 erg/cm2,
and a 64-ms peak flux, measured from T0+3.200s,
of (5.0 � 0.3)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+38.656 s)
is best fit in the 50 keV - 15 MeV range
by the cutoff power law model with the following parameters:
the photon index alpha = -1.04 � 0.04,
the peak energy Ep = 1380 � 120 keV,
chi2 = 96/90 dof.
The spectrum at the maximum count rate
(measured from T0+0.256 to T0+5.888 s)
is best fit in the 50 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
by the cutoff power law model with the following parameters:
the photon index alpha = -0.97 � 0.04,
the peak energy Ep = 1429 � 84 keV,
chi2 = 72/79 dof.
All the quoted results are preliminary.