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 20.712 sec. to 154.752 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.39874 ( -0.124602 0.125062 )
Norm@50keV : 1.84512E-03 ( -0.000132125 0.000132033 )
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#Fit statistic : Chi-Squared = 50.11 using 59 PHA bins.
# Reduced chi-squared = 0.8791 for 57 degrees of freedom
# Null hypothesis probability = 7.292438e-01
Photon flux (15-150 keV) in 134 sec: 0.224641 ( -0.016822 0.016862 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38998e-06 ( -1.85105e-07 1.8607e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 20.712 sec. to 154.752 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.942267 ( -0.497272 0.580261 )
Epeak [keV] : 122.827 ( -41.5261 -122.826 )
Norm@50keV : 3.05502E-03 ( -0.00125559 0.00261085 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.81 using 59 PHA bins.
# Reduced chi-squared = 0.8537 for 56 degrees of freedom
# Null hypothesis probability = 7.738346e-01
Photon flux (15-150 keV) in 134 sec: 0.219688 ( -0.017819 0.017746 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32308e-06 ( -2.01911e-07 2.0136e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 25.704 sec. to 26.704 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.795291 ( -0.422012 0.487892 )
Norm@50keV : 6.29325E-03 ( -0.00181609 0.00174449 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.71 using 59 PHA bins.
# Reduced chi-squared = 1.223 for 57 degrees of freedom
# Null hypothesis probability = 1.204065e-01
Photon flux (15-150 keV) in 1 sec: 0.723419 ( -0.196311 0.199705 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.36953e-08 ( -1.91358e-08 1.92313e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 25.704 sec. to 26.704 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.288678 ( -1.28263 3.29278 )
Epeak [keV] : 126.197 ( -56.1118 -126.207 )
Norm@50keV : 1.81383E-02 ( -0.0181351 0.324032 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.79 using 59 PHA bins.
# Reduced chi-squared = 1.228 for 56 degrees of freedom
# Null hypothesis probability = 1.171652e-01
Photon flux (15-150 keV) in 1 sec: 0.698419 ( -0.20041 0.204387 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.07115e-08 ( -2.14248e-08 2.04098e-08 ) ergs/cm2
Time-resolved spectra
