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GCN Circular 6638

Subject
GRB 070714B: Swift/BAT and Suzaku/WAM joint spectral analysis
Date
2007-07-19T13:55:47Z (17 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira (Hiroshima U.),
K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.),
Y. Terada, T. Tamagawa (RIKEN), K. Morigami, N. Kodaka, K. Onda,
M. Tashiro, M. Suzuki, Y. Urata, A. Endo (Saitama U.), T. Enoto,
R. Miyawaki, K. Nakawaza, K. Makishima (Univ. of Tokyo), E. Sonoda,
M.Yamauchi, S. Maeno, 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, 

T. Sakamoto (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC), 
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), 
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), 
A. Parsons (GSFC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), 
J. Tueller (GSFC), T. Ukwatta (GWU)
on behalf of the Swift-BAT team, 

report:

We performed the Swift/BAT, and Suzaku/WAM joint fit spectral 
analysis of GRB 070714B (Swift-BAT trigger #284856; Racusin, et al., 
GCN Circ. 6620).  The time interval of the spectral data for each 
instrument is chosen from T0(WAM) to T0(WAM)+2 sec where 
T0(WAM) is the trigger time of WAM at 04:59:29.247 UTC.  
The energy ranges which we used in the joint spectral analysis 
are 14-150 keV and 100-2000 keV for Swift/BAT and Suzaku/WAM 
respectively.  The spectral data of two instruments are fit 
with the spectral model multiplied by the constant factor to 
take into account the systematic uncertainties in the response 
matrices of each instrument.  

The spectrum is well fit with a power-law with exponential cutoff 
model (dN/dE ~ E^{alpha} * exp(-(2+alpha)*E/Epeak)).  The constant 
factors of each instrument agree within 10%.  No systematic residual 
from the best fit model is seen in the spectral data of each instrument.  
The best fit spectral parameters are: alpha = -0.86 +- 0.10 and 
Epeak = 1120 (-380/+780) keV (chi2/dof = 64/69).  The energy fluence 
in the 15-2000 keV band calculated by a power-law with exponential 
cutoff model for this two-second interval is 3.7 (-0.6/+1.3) x 10^-6 erg/cm2 
(assuming the constant factor of the BAT is fixed to 1). 

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