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GRB 140825A

GCN Circular 16752

Subject
IPN Triangulation of GRB 140825A (very intense/long)
Date
2014-08-28T18:06:34Z (11 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on
behalf of the GRS-Odyssey 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,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on
behalf of the Swift-BAT team, and

D. M. Smith, on behalf of the RHESSI GRB team, report:

The long-duration, very intense GRB 140825A has been observed by 
Konus-Wind, MESSENGER (GRNS), Mars Odyssey (HEND), Swift (BAT), RHESSI, 
and INTEGRAL (SPI-ACS), so far, at about 24925 s UT (06:55:25). The 
burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
   ---------------------------------------------
    RA(2000), deg                 Dec(2000), deg
   ---------------------------------------------
   Center:
     88.715 (05h 54m 51s) -11.830 (-11d 49' 48")
   Corners:
     88.611 (05h 54m 27s) -11.630 (-11d 37' 48")
     88.657 (05h 54m 38s) -11.950 (-11d 57' 01")
     88.818 (05h 55m 16s) -12.029 (-12d 01' 46")
     88.772 (05h 55m 05s) -11.710 (-11d 42' 36")
   ---------------------------------------------
The error box area is 169 sq. arcmin, and its maximum
dimension is 27 arcmin (the minimum one is 9 arcmin).

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB140825_T24925/IPN/

The time history and spectrum will be given in a forthcoming GCN Circular.

GCN Circular 16755

Subject
Konus-Wind observation of GRB 140825A
Date
2014-08-29T17:23:14Z (11 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@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, intense GRB 140825A
(IPN triangulation: Hurley et al., GCN 16752)
triggered Konus-Wind at T0=24925.66 s UT (06:55:25.660).

The burst light curve shows several peaks with a total duration of ~14 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 3.7(-0.2,+0.2)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+1.984 s,
of 1.4(-0.2,+0.2)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+10.752 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.94(-0.07,+0.08),
the high-energy photon index beta = -3.42(-1.36,+0.40),
the peak energy Ep = 142(-7,+7) keV,
chi2 = 86/84 dof.

The spectrum near the peak count rate
(measured from T0+2.048 to T0+2.560 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.44(-0.15,+0.21),
the high-energy photon index beta = -3.42(-1.61,+0.59),
the peak energy Ep = 208(-23,+18) keV,
chi2 = 41/44 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140825_T24925/

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

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