GRB 131011B
GCN Circular 15366
Subject
IPN triangulation of GRB 131011B (Swift Trigger 574266)
Date
2013-10-24T16:05:11Z (12 years ago)
From
Kevin Hurley at UCBerkeley/SSL <khurley@ssl.berkeley.edu>
K. Hurley and J. Goldsten, on behalf of the MESSENGER GRB team,
S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C.
Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and
S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of
the Swift-BAT team, report:
Swift trigger 574266 (Beardmore et al., GCN 15323), was also observed by
MESSENGER GRNS, Konus-Wind, and INTEGRAL SPI-ACS. We have triangulated it
to a preliminary, 3 sigma error box whose area is ~40000 sq. arcmin., and
whose coordinates are:
CENTER:
RA(2000) DEC(2000)
113.600 deg. = 7 h 34 m 24 s 80.277 deg. = 80 o 16 ' 38"
CORNERS:
119.660 deg. = 7 h 58 m 38 s 72.631 deg. = 72 o 37 ' 51 "
56.573 deg. = 3 h 46 m 17 s 87.670 deg. = 87 o 40 ' 13 "
118.606 deg. = 7 h 54 m 25 s 70.117 deg. = 70 o 7 ' 01 "
81.813 deg. = 5 h 27 m 15 s 86.290 deg. = 86 o 17 ' 23 "
This error box is also consistent with the Konus ecliptic latitude
determination. It lies approximately 80 degrees from the Swift BAT
localization (GCN 15323), confirming that Swift trigger 574266 was
indeed a GRB ~68 degrees from the center of the BAT field of view, and
unrelated to VY Ari. Improvements in the IPN localization are possible.
GCN Circular 15368
Subject
Konus-Wind observation of GRB 131011B
Date
2013-10-24T17:52:37Z (12 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long-duration GRB 131011B
(Swift-BAT trigger 574266: Beardmore, et al., GCN 15323;
IPN triangulation: Hurley at al., GCN 15366)
triggered Konus-Wind at T0=80208.914 s UT (22:16:48.914).
The burst light curve shows a broad multi-peaked pulse from ~T0-35 s
till ~T0+40 s.
The emission is seen up to ~12 MeV.
The K-W ecliptic latitude response indicates the source located
at medium-to-high Northern ecliptic latitude,
which is at odds with the BAT position reported in GCN 15323,
however, consistent with the recent IPN box (GCN 15366).
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131014_T80208/
As observed by Konus-Wind, the burst
had a fluence of (7.7 � 0.3)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.212 s,
of (6.0 � 0.6)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+31.744 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.68 � 0.06,
the high energy photon index beta = -2.21 � 0.09,
the peak energy Ep = 270 � 18 keV,
chi2 = 110/97 dof.
The spectrum near the maximum count rate
(measured from T0 to T0+7.936 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.63 � 0.04,
the high energy photon index beta = -2.22 � 0.14,
the peak energy Ep = 331 � 33 keV,
chi2 = 131/97 dof.
All the quoted values are preliminary.