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 -1.008 sec. to 171.536 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.37558 ( -0.088271 0.0883 )
Norm@50keV : 1.56413E-03 ( -7.44954e-05 7.43979e-05 )
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#Fit statistic : Chi-Squared = 43.94 using 59 PHA bins.
# Reduced chi-squared = 0.7709 for 57 degrees of freedom
# Null hypothesis probability = 8.975208e-01
Photon flux (15-150 keV) in 172.5 sec: 0.189456 ( -0.009282 0.009303 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.62078e-06 ( -1.39305e-07 1.40115e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.008 sec. to 171.536 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.25748 ( -0.162714 0.336405 )
Epeak [keV] : 330.081 ( -330.082 -330.082 )
Norm@50keV : 1.78299E-03 ( -0.000281593 0.00077667 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.54 using 59 PHA bins.
# Reduced chi-squared = 0.7775 for 56 degrees of freedom
# Null hypothesis probability = 8.875840e-01
Photon flux (15-150 keV) in 172.5 sec: 0.188131 ( -0.009912 0.009909 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.59597e-06 ( -1.54738e-07 1.53944e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.212 sec. to 2.212 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.32538 ( -0.158419 0.157659 )
Norm@50keV : 1.33950E-02 ( -0.00126467 0.00126086 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.72 using 59 PHA bins.
# Reduced chi-squared = 1.135 for 57 degrees of freedom
# Null hypothesis probability = 2.252440e-01
Photon flux (15-150 keV) in 1 sec: 1.60579 ( -0.15022 0.15031 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.31583e-07 ( -1.405e-08 1.41843e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.212 sec. to 2.212 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.806379 ( -0.575782 0.682046 )
Epeak [keV] : 118.368 ( -41.4931 -118.368 )
Norm@50keV : 2.42270E-02 ( -0.011324 0.0271302 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.49 using 59 PHA bins.
# Reduced chi-squared = 1.116 for 56 degrees of freedom
# Null hypothesis probability = 2.566618e-01
Photon flux (15-150 keV) in 1 sec: 1.57472 ( -0.07767 0.15448 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.27022e-07 ( -1.50834e-08 1.51585e-08 ) ergs/cm2
Time-resolved spectra
