Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from -4.552 sec. to 31.188 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.40725 ( -0.194169 0.19183 )
Norm@50keV : 1.39783E-03 ( -0.000167289 0.000165608 )
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#Fit statistic : Chi-Squared = 67.29 using 59 PHA bins.
# Reduced chi-squared = 1.180 for 57 degrees of freedom
# Null hypothesis probability = 1.653768e-01
Photon flux (15-150 keV) in 35.74 sec: 0.170514 ( -0.018975 0.018976 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.82075e-07 ( -6.54224e-08 6.7054e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.552 sec. to 31.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.339956 ( -0.870656 1.07681 )
Epeak [keV] : 69.9283 ( -16.6539 103.328 )
Norm@50keV : 5.33913E-03 ( -0.00533913 0.0147595 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.76 using 59 PHA bins.
# Reduced chi-squared = 1.121 for 56 degrees of freedom
# Null hypothesis probability = 2.492002e-01
Photon flux (15-150 keV) in 35.74 sec: 0.162111 ( -0.019943 0.020076 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.24037e-07 ( -7.20518e-08 7.94339e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 5.320 sec. to 6.320 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.35043 ( -0.316653 0.312093 )
Norm@50keV : 5.63928E-03 ( -0.00105324 0.0010351 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.82 using 59 PHA bins.
# Reduced chi-squared = 1.032 for 57 degrees of freedom
# Null hypothesis probability = 4.087139e-01
Photon flux (15-150 keV) in 1 sec: 0.679441 ( -0.118449 0.11845 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.50795e-08 ( -1.17574e-08 1.21903e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 5.320 sec. to 6.320 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.00667 ( -1.51052 1.37837 )
Epeak [keV] : 135.411 ( -135.411 -135.411 )
Norm@50keV : 8.60857E-03 ( -0.00395471 0.0373698 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.55 using 59 PHA bins.
# Reduced chi-squared = 1.045 for 56 degrees of freedom
# Null hypothesis probability = 3.821214e-01
Photon flux (15-150 keV) in 1 sec: 0.668498 ( -0.123607 0.121963 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.28628e-08 ( -1.35304e-08 1.37442e-08 ) ergs/cm2
Time-resolved spectra
