Gamma-ray Burst 140825A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #16752
  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
  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.