{
  "bibcode": "2006GCN..5477....1S",
  "body": "T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), S. D. Barthelmy (GSFC), \nJ. Cummings (GSFC/ORAU), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), \nA. Parsons (GSFC), J. Tueller (GSFC), L. Barbier (GSFC), \nE. Fenimore (LANL), D. Hullinger (BYU-Idaho), M. Koss (GSFC/UMD), \nC. Markwardt (GSFC/UMD), D. Palmer (LANL), M. Stamatikos (GSFC/ORAU), \non behalf of the Swift-BAT team, \n\nS. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, \nand T. Cline on behalf of the Konus-Wind team, \n\nM. Ohno, T. Takahashi, T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.),\nK. Yamaoka, S. Sugita (Aoyama Gakuin U.), \nY. Terada, T. Tamagawa, M. Suzuki (RIKEN), \nK. Abe, K. Onda, Y. Urata, M. Suzuki, M. Tashiro (Saitama U.),\nS. Hong (Nihon U.), K. Nakazawa, T. Takahashi (ISAS/JAXA), \nT. Enoto, R. Miyawaki, K. Kokubun, K. Makishima (Univ. of Tokyo)\non behalf of the Suzaku-WAM team, \n\nreport:\n\nWe performed the Swift/BAT, Konus-Wind, and Suzaku/WAM joint fit spectral \nanalysis of GRB 060813 (Swift-BAT trigger #224364; Moretti, et al., \nGCN Circ. 5442).  The time interval of the spectral data for each instrument \nis chosen as the same interval as the Konus-Wind time-averaged spectrum \nreported by Golenetskii et al. (GCN Circ. 5446).  The energy ranges which we \nused in the joint spectral analysis are 14-150 keV, 20-1000 keV, \nand 100-1000 keV, for Swift/BAT, Konus-Wind and Suzaku/WAM respectively.  \nThe spectral data of three instruments are fitted with the spectral model \nmultiplied by the constant factor to take into account the systematic \nuncertainties in the response matrices of each instrument.  \n\nThe spectrum is well fitted with a power-law time exponential cutoff model \n(dN/dE ~ E^{alpha} * exp(-(2+alpha)*E/Epeak)).  The constant factors of each \ninstrument agree within 10%.  No systematic residual from the best fit model \nis seen in the spectral data of each instrument.  The best fit spectral \nparameters are: alpha = -0.83 +- 0.05 and Epeak = 240 (-10/+11) keV \n(chi2/dof = 135/125).  Although there is no significant improvement in the \nfit, the best fit parameters in the Band function are: the low-energy \nphoton index alpha = -0.79 +- 0.06, the high energy photon index \nbeta = -2.71 (-0.70/+0.24) and Epeak = 230 (-14/+15) keV \n(chi2/dof = 133/124).  The energy fluence in the 15-1000 keV band calculated \nby the Band function is 1.22 +- 0.05 x 10^-5 erg/cm2 (in case the constant \nfactor of the Konus-Wind is fixed to 1).  The spectral paramters in a \npower-law time exponential cutoff model for Swift/BAT and Suzaku/WAM were \nreported by Cummings et al. (GCN Circ. 5443) and by Yamaoka, et al. \n(GCN Circ. 5462).  The Konus-Wind best fit spectral parameters for a \npower-law time exponential cutoff model are:  alpha = -0.65 (-0.12, +0.11), \nEpeak = 214 (-15, +17) keV (chi2/dof = 81/59).  Our joint fit spectral \nparameters in a power-law time exponential cutoff model are consistent \nwithin 90% confidence level with the spectral parameters derived by individual \ninstruments.  However, we do see a systematic difference in the spectral \nparameters in the Band function fit especially in the low energy photon \nindex alpha.  We are still working on the cross-calibration among three \ninstruments.  \n\nAll the quoted errors are at the 90% confidence level. \n\n[GCN OPS NOTE(25aug06): Per author's request, the last two words were added\nto the Subject line.]",
  "circularId": 5477,
  "createdOn": 1156509154000,
  "email": "takanori@milkyway.gsfc.nasa.gov",
  "subject": "GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis",
  "submitter": "Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 060813"
}