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 0.000 sec. to 0.128 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.992083 ( -0.0891914 0.089597 )
Norm@50keV : 0.143079 ( -0.00748925 0.00748869 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.32 using 59 PHA bins.
# Reduced chi-squared = 1.128 for 57 degrees of freedom
# Null hypothesis probability = 2.358180e-01
Photon flux (15-150 keV) in 0.128 sec: 16.4658 ( -0.8623 0.8624 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98619e-07 ( -1.23158e-08 1.23945e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.675106 ( -0.339679 0.372193 )
Epeak [keV] : 222.886 ( -92.5828 -222.887 )
Norm@50keV : 0.203659 ( -0.0554964 0.10073 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.83 using 59 PHA bins.
# Reduced chi-squared = 1.104 for 56 degrees of freedom
# Null hypothesis probability = 2.758933e-01
Photon flux (15-150 keV) in 0.128 sec: 16.2972 ( -0.8846 0.8823 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.94173e-07 ( -1.34852e-08 1.33896e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.434 sec. to 0.566 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.03872 ( -0.119932 0.12135 )
Norm@50keV : 1.91597E-02 ( -0.00130952 0.00130942 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.63 using 59 PHA bins.
# Reduced chi-squared = 0.9234 for 57 degrees of freedom
# Null hypothesis probability = 6.395168e-01
Photon flux (15-150 keV) in 1 sec: 2.21107 ( -0.15266 0.15272 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.04433e-07 ( -1.60464e-08 1.61744e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.434 sec. to 0.566 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.838235 ( -0.259232 0.489827 )
Epeak [keV] : 313.166 ( -313.178 -313.178 )
Norm@50keV : 2.38624E-02 ( -0.00574322 0.0161506 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.05 using 59 PHA bins.
# Reduced chi-squared = 0.9295 for 56 degrees of freedom
# Null hypothesis probability = 6.250831e-01
Photon flux (15-150 keV) in 1 sec: 2.19372 ( -0.15766 0.15739 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.01572e-07 ( -1.75075e-08 1.73402e-08 ) ergs/cm2
Time-resolved spectra
