Gamma-ray Burst 120522A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #13340
  K. Hurley on behalf of the Mars Odyssey and MESSENGER GRB teams,
  J. Goldsten, on behalf of the MESSENGER GRNS GRB team,
  I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
  S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration, bright GRB 120522A has been observed by Konus-Wind, MESSENGER (GRNS), and Mars Odyssey (HEND), so far, at about 11467 s UT (03:11:07).
  We have triangulated it to a preliminary, 3 sigma error box whose coordinates are:

    ---------------------------------------------
     RA(2000), deg                 Dec(2000), deg
    ---------------------------------------------
    Center:
     165.996 (11h 03m 59s) -62.094 (-62d 05' 37")
    Corners:
     165.772 (11h 03m 05s) -61.976 (-61d 58' 35")
     165.879 (11h 03m 31s) -62.218 (-62d 13' 06")
     166.222 (11h 04m 53s) -62.211 (-62d 12' 38")
     166.112 (11h 04m 27s) -61.969 (-61d 58' 08")
    ---------------------------------------------
  

  The error box area is 141 sq. arcmin, and its maximum dimension is 19 arcmin. The Sun distance is ~116 deg.
  This box may be improved.
  The time history and spectrum will be given in a forthcoming GCN Circular.
• GCN Circular #13341
  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 GRB 120522A (IPN localization: Hurley at al., GCN 13340) triggered Konus-Wind at T0=11467.377s UT (03:11:07.377)
  The light curve shows multiple partly overlapped pulses. A total duration of the burst is ~13 s. The emission is seen up to ~6 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120522_T11467/
  As observed by Konus-Wind the burst had a fluence of 2.5(-0.2,+0.2)x10-5 erg/cm2, and a 64-ms peak flux, measured from T0+6.528 s, of 9.3(-0.9,+0.9)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-integrated spectrum of the burst (measured from T0 to T0+78.086 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which

  alpha = -0.88 (-0.05, +0.05),
  and Ep = 381(-33, +40) keV,
  chi2 = 100.1/84 dof.
  

  The spectrum at the maximum count rate (measured from T0+0.256 to T0+7.168 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which

  alpha = -0.79 (-0.05, +0.05),
  and Ep = 379(-32, +37) keV,
  chi2 = 89.5/84 dof.
  

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