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 -13.392 sec. to 55.832 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.23926 ( -0.030772 0.0308713 )
Norm@50keV : 1.87600E-02 ( -0.000308644 0.000307866 )
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#Fit statistic : Chi-Squared 47.26 using 59 bins.
Reduced chi-squared = 0.829123
# Null hypothesis probability of 8.18e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 69.22 sec: 2.21500 ( -0.04101 0.04122 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.30344e-05 ( -2.0662e-07 2.07232e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.392 sec. to 55.832 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23491 ( -0.0306619 0.0315365 )
Epeak [keV] : 9999.36 ( -9999.36 -9999.36 )
Norm@50keV : 1.88293E-02 ( -0.000293811 0.00172402 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 47.32 using 59 bins.
Reduced chi-squared = 0.845
# Null hypothesis probability of 7.89e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 69.22 sec: 2.21917 ( -0.04606 0.03611 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.18444e-06 ( -2.32201e-07 8.83642e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.240 sec. to 1.240 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.824163 ( -0.0426581 0.0429028 )
Norm@50keV : 0.217964 ( -0.00519388 0.00517721 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 52.03 using 59 bins.
Reduced chi-squared = 0.912807
# Null hypothesis probability of 6.62e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 25.0326 ( -0.5879 0.5882 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.52185e-06 ( -6.34644e-08 6.35039e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.240 sec. to 1.240 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.747172 ( -0.0913525 0.166692 )
Epeak [keV] : 999.584 ( -999.962 -999.962 )
Norm@50keV : 0.234600 ( -0.00533861 0.0391374 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 51.42 using 59 bins.
Reduced chi-squared = 0.918214
# Null hypothesis probability of 6.49e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 24.9502 ( -0.61 0.5848 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51495e-06 ( -6.521e-08 5.98885e-08 ) ergs/cm2
Time-resolved spectra
