Gamma-ray Burst 080122

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #7211
  K. Hurley and T. Cline on behalf of the Mars Odyssey, Konus, and MESSENGER GRB teams,
  W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on behalf of the GRS-Odyssey 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 on behalf of the Konus-Wind team,
  J. Goldsten, on behalf of the MESSENGER GRNS GRB team,
  K. Yamaoka, M. Ohno, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team,
  J. Cummings, S. Barthelmy, N. Gehrels, and H. Krimm, on behalf of the Swift-BAT team,
  E. Del Monte, Y. Evangelista, I. Lapshov, M. Rapisarda, A. Giuliani, F. Fuschino, and M. Marisaldi, on behalf of the AGILE Team, and
  A. von Kienlin, G. Lichti, and A. Rau, on behalf of the INTEGRAL SPI-ACS GRB team, report:
  Mars Odyssey (GRS), Konus-Wind, MESSENGER (GRNS), Suzaku-WAM, Swift-BAT, AGILE-MCAL, and INTEGRAL SPI-ACS observed the long-duration GRB 080122 at about 66764 s UT (18:32:44). The burst was outside the coded field of view of the BAT. The time history consists of several multipeaked pulses with a total duration of ~150 sec.
  We have triangulated it to the following, preliminary 3-sigma error box:

  -----------------------------------------------
       RA(2000), deg            Dec(2000), deg
  -----------------------------------------------
  Center:
    191.352 (12h 45m 24s)   +27.014 (+27d 00' 49")
  Corners:
    191.825 (12h 47m 18s)   +27.508 (+27d 30' 30")
    191.786 (12h 47m 09s)   +27.830 (+27d 49' 47")
    190.880 (12h 43m 31s)   +26.512 (+26d 30' 44")
    190.914 (12h 43m 39s)   +26.181 (+26d 10' 52")
  -----------------------------------------------
  

  The error box area is 1106 sq. arcmin. Some improvement is possible.
  Preliminary analysis of the Konus-Wind data yields a burst fluence of ~5x10^-5 erg/cm2 (in the 20 keV - 1 MeV range), and an Epeak of the time-integrated spectrum of ~260 keV.
  Detailed spectral parameters will be reported later.
• GCN Circular #7218
  T. Uehara, M. Ohno, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.), T. Tamagawa (RIKEN), K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.), M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda, M. Suzuki, N. Kodaka, K. Morigami (Saitama U.), T. Enoto, R. Miyawaki, K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara (Univ. of Miyazaki), M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report:
  The IPN localized long GRB 080122 (Hurley et al., GCN 7211) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2008-01-22 18:32:45 UT (=T0).
  The observed light curve shows a multi-peaked structure starting at T0-2 s, ending at T+98 s, with a duration (T90) of about 100 seconds. The fluence in 100-1000 keV was 2.5 x 10^-5 erg/cm^2. The 1-s peak flux measured from T0+5 s was 5.2 photons/cm^2/s in the same energy range.
  Preliminary result shows that the time-averaged spectrum from T0-4 s to T0+119 s is well fit by a power-law with exponential cutoff model:

    dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak)
    alpha       1.28 (+0.43, -0.54), and
    Epeak       420  (+326, -192) keV (chi2/dof = 15.8/24).
  

  All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included.
  The light curve data for this burst is available at: http://www.astro.isas.ac.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
• GCN Circular #7219
  S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report:
  The long GRB 080122 (Hurley et al., GCN 7211) triggered Konus-Wind at T0=66764.605 s UT (18:32:44.605).
  The burst light curve shows three multipeaked pulses with a total duration of ~150 s.
  As observed by Konus-Wind the burst had a fluence of 6.35(-3.39, +3.50)x10^-5 erg/cm2, and a 64-ms peak flux measured from T0+6.768 s of (4.80 +/- 0.95)x10^-6 erg/cm2/s (both in the 20 keV - 1 MeV energy range).
  The time-integrated spectrum of the burst (from T0 to T0+112.384 s) is well fitted (in the 20 keV - 1 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.27 +/- 0.10 and Ep = 259(-33, +46) keV (chi2 = 58.1/60 dof). Fitting by GRBM (Band) model yields: the low-energy photon index is alpha = -1.21(-0.11, +0.12), the high energy photon index beta = -2.36(-0.68, +0.24), the peak energy Ep = 227(-33, +43) keV (chi2 = 54.2/59 dof).
  The spectrum of the most intense part (from T0 to T0+14.080 s) is well fitted (in the same range) by a power law with exponential cutoff model with alpha = -1.00 +/- 0.07 and Ep = 341(-29, +35) keV (chi2 = 46.8/60 dof). Fitting by GRBM (Band) model yields only an upper limit on the high energy photon index: beta < -2.27. The fluence of this part is (2.42+/-0.10)x10^-5 erg/cm2.
  All the quoted errors are at the 90% confidence level.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080122_T66764/
• GCN Circular #7220
  A. Pelangeon & J-L. Atteia (LATT-OMP) report:
  We used the spectral parameters of the most intense part of GRB 080122 provided by Golenetskii et al. (GCNC 7219) to compute the spectral pseudo-redshift(**) of this burst detected by the IPN (Hurley et al., GCNC 7211).
  We find a pseudo-redshift pz= 1.93 +/- 0.25
  (**) cf. http://www.ast.obs-mip.fr/grb/pz