Gamma-ray Burst 140906C

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #16801
  S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
  S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team,
  K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB 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
  G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, and M. Marisaldi, on behalf of the AGILE MCAL team, report:
  The short-duration, hard spectrum, intense GRB 140906C has been observed by Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), AGILE (MCAL), and MESSENGER (GRNS), so far, at about 85869 s UT (23:51:09). 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:
     314.964 (20h 59m 51s)  +2.354 ( +2d 21' 14")
    Corners:
     315.062 (21h 00m 15s)  +0.809 ( +0d 48' 31")
     314.873 (20h 59m 30s)  +0.650 ( +0d 39' 00")
     314.902 (20h 59m 36s)  +3.944 ( +3d 56' 39")
     315.099 (21h 00m 24s)  +4.119 ( +4d 07' 07")
    ---------------------------------------------
  

  The error box area is 2273 sq. arcmin, and its maximum dimension is 4.6 deg (the minimum one is 12 arcmin). The Sun distance was 148 deg.
  This box can be improved.
  The time history and spectrum will be given in a forthcoming GCN Circular.
• GCN Circular #16805
  K. Hurley, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
  S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team,
  S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team,
  J. Goldsten, on behalf of the MESSENGER NS GRB team,
  A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
  G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, and M. Marisaldi, on behalf of the AGILE MCAL team, and
  D. M. Smith, on behalf of the RHESSI GRB team, report:
  The short-duration, hard spectrum GRB 140906=D1 (Golenetskii et al., GCN=20 16801) was also observed by RHESSI and Odyssey. Using Odyssey data=20 reduces the size of the previous error box by about a factor of 6:

    ---------------------------------------------
     RA(2000), deg                 Dec(2000), deg
    ---------------------------------------------
    Center:
     314.961 (20h 59m 51s)  +1.939 ( +1d 56' 21")
    Corners:
     315.057 (21h 00m 14s)  +1.949 ( +1d 56' 57")
     314.869 (20h 59m 29s)  +2.439 ( +2d 26' 22")
     314.866 (20h 59m 28s)  +1.929 ( +1d 55' 45")
     315.057 (21h 00m 14s)  +1.428 ( +1d 25' 41")
    ---------------------------------------------
  

  The error box area is 355 sq. arcmin, and its maximum dimension is 1.0 deg (the minimum one is 11 arcmin).
  A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB140906_T85872/IPN/
  Some further improvement in this error box is possible.
• GCN Circular #16807
  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 short-duration GRB 140906C (IPN triangulation: Golenetskii et al., GCN 16801 and Hurley et al., GCN 16805) triggered Konus-Wind at T0=85872.815 s UT (23:51:12.815).
  The burst light curve shows two peaks with a total duration of ~0.16 s. The emission is seen up to ~2 MeV.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB140906_T85872/
  As observed by Konus-Wind, the burst had a fluence of 2.2(-0.5,+0.6)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.064 s, of 4.4(-1.4,+1.7)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-averaged spectrum of the burst (measured from T0 to T0+0.128 s) is best fit in the 20 keV - 10 MeV range by a simple power law function with index = -1.76 (-0.11,+0.13) (chi2 = 24.2/23 dof). Fitting by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields the same alpha and a lower limit on the Ep: Ep > 248 keV (chi2 = 22/22 dof).
  All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.