{
  "bibcode": "2008GCN..8256....1P",
  "body": "V. Pal'shin, S. Golenetskii, R.Aptekar, E. Mazets, D. Frederiks, and\nT. Cline on behalf of the Konus-Wind team,\n\nT. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC),\nW. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),\nJ. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),\nH. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),\nD. Palmer (LANL), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),\nJ. Tueller (GSFC), and T. Ukwatta (GWU)\non behalf of the Swift-BAT team,\n\nreport:\n\nWe performed the Konus-Wind and the Swift/BAT joint spectral analysis\nof GRB 080913 (Swift/BAT trigger #324561: Schady et al., GCN Circ. 8217,\nStamatikos et al. GCN Circ. 8222).\nSince the Konus-Wind observed this GRB in the waiting mode, we only\nhave 3 channel spectral data for the Konus-Wind which cover the energy\nrange from 20 keV to 1.3 MeV.  Therefore, the joint spectral analysis of\nthe Konus-Wind and the Swift/BAT data enables to derive the broad-band\nspectral parameters of this burst.\n\nThe time interval of the spectral data for each instrument is chosen\nfrom  T0(BAT)-4.1 to T0(BAT)+4.7 sec where T0(BAT) is the trigger time\nof BAT at 06:46:54.1 UTC.  The energy ranges which we used in the joint\nspectral analysis are 20-1300 keV and 14-150 keV for the Konus-Wind and\nthe Swift/BAT respectively.  The spectral data of two instruments are\nfit with the spectral model multiplied by the constant factor to take\ninto account the systematic effective area uncertainties in the response\nmatrices of each instrument.\n\nThe spectrum is well fit with a power-law with exponential cutoff model:\ndN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak). The constant factors of each\ninstrument agree within 5%.  No systematic residual from the best fit\nmodel is seen in the spectral data of each instrument.  The best fit\nspectral parameters are: alpha = -0.89(-0.46, +0.65) and Epeak = 131\n(-48/+225) keV (chi2/dof = 43.7/58).  The best fit spectral parameters\nfor the Band function fixing beta=-2.5 are: alpha = -0.82(-0.53, +0.75)\nand Epeak = 121 (-39/+232) keV (chi2/dof = 43.9/58).  The energy fluence\nin the 15-1000 keV band calculated by a power-law with exponential\ncutoff model for this 8.8 sec interval is 8.5(-2.2, +6.0)x10^-7 erg/cm2\n\nAll the quoted errors are at the 90% confidence level.\n\nAssuming z = 6.7 (Fynbo et al., GCN Circ. 8225) and a standard cosmology\nmodel with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73, the\nisotropic energy  release is E_iso ~7x10^52 erg in 1 keV to 10 MeV at\nthe GRB rest frame extrapolating the best Band function fit fixing\nbeta=-2.5.\n\nLooking only at the parameters of the prompt emission, namely T90~1 sec\nand Ep ~900 keV in the GRB rest frame, this burst could be classified as\na short burst.",
  "circularId": 8256,
  "createdOn": 1221644513000,
  "email": "val@mail.ioffe.ru",
  "subject": "GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis",
  "submitter": "Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>",
  "eventId": "GRB 080913"
}