{
  "bibcode": "2009GCN..9422....1S",
  "body": "T. 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)\n\nV. Pal'shin, S. Golenetskii, R.Aptekar, E. Mazets, D. Frederiks, and\nT. Cline on behalf of the Konus-Wind team,\nreport:\n\nWe performed the Konus-Wind and the Swift/BAT joint spectral analysis\nof GRB 090516A (Swift/BAT trigger #352190: Rowlinson et al., GCN Circ. \n9374, Baumgartner et al. GCN Circ. 9384).  Since the Konus-Wind observed \nthis GRB in the waiting mode, we only have 3 channel spectral data for \nthe Konus-Wind which cover the energy range from 20 keV to 1.2 MeV.  The \njoint spectral analysis of the Konus-Wind and the Swift/BAT data \nallows us to derive the broad-band spectral parameters of this burst.\n\nThe time interval of the spectral data for each instrument is chosen\nfrom T0(BAT)-12.2 to T0(BAT)+96.7 sec where T0(BAT) is the trigger time\nof BAT at 08:27:50.8 UTC.  The energy ranges which we used in the joint\nspectral analysis are 20-1200 keV and 14-150 keV for the Konus-Wind and\nthe Swift/BAT respectively.  The spectral data of two instruments are\nfitted 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 fitted with a power-law with exponential cutoff \nmodel: dN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak). The constant factors \nof each instrument agree within 10%.  No systematic residual from the \nbest fit model is seen in the spectral data of each instrument.  The \nbest fit spectral parameters are: alpha = -1.5 (-0.3/+0.2) and Epeak \n= 190 (-65/+230) keV (chi2/dof = 54/56).  The best fit spectral \nparameters for the GRB (Band) model fixing beta = -2.5 are: \nalpha = -1.5 (-0.2/+0.3), and Epeak = 190 (-75/+270) keV (chi2/dof = 55/56).\nThe energy fluence in the 15-1200 keV band calculated by a power-law \nwith exponential cutoff model for this 107.9 sec interval is \n(1.5 +/- 0.3)x10^-5 erg/cm2.\n\nAssuming z = 4.109 (de Ugarte Postigo et al. GCN Circ. 9383) and a standard \ncosmology model with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = \n0.73, the isotropic energy release is E_iso = 6.5 (-1.1/+1.4) x10^53 erg in \n1 keV to 10 MeV at the GRB rest frame extrapolating the best Band function fit \nfixing beta = -2.5.\n\nThe Konus-Wind light curve of this GRB is available at \nhttp://www.ioffe.ru/LEA/GRBs/GRB090516/ \n\nAll the quoted errors are at the 90% confidence level.",
  "circularId": 9422,
  "createdOn": 1243186049000,
  "email": "takanori.sakamoto-1@nasa.gov",
  "subject": "GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis",
  "submitter": "Takanori Sakamoto at NASA/GSFC  <takanori.sakamoto-1@nasa.gov>",
  "eventId": "GRB 090516A"
}