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 -82.456 sec. to 136.620 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.681 ( -0.0565556 0.0563754 )
Norm@50keV : 4.13366E-03 ( -0.000119507 0.00011936 )
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#Fit statistic : Chi-Squared = 59.35 using 59 PHA bins.
# Reduced chi-squared = 1.041 for 57 degrees of freedom
# Null hypothesis probability = 3.898786e-01
Photon flux (15-150 keV) in 219.1 sec: 0.545424 ( -0.017459 0.017533 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.40005e-06 ( -2.52215e-07 2.52662e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -82.456 sec. to 136.620 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55263 ( -0.162721 0.225666 )
Epeak [keV] : 182.814 ( -112.693 -182.827 )
Norm@50keV : 4.75659E-03 ( -0.000708026 0.00129188 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.33 using 59 PHA bins.
# Reduced chi-squared = 1.042 for 56 degrees of freedom
# Null hypothesis probability = 3.897251e-01
Photon flux (15-150 keV) in 219.1 sec: 0.539628 ( -0.01981 0.0199 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.31136e-06 ( -2.92691e-07 2.91094e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 27.452 sec. to 28.452 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.49841 ( -0.0891434 0.0885831 )
Norm@50keV : 5.25714E-02 ( -0.00259986 0.00259292 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.68 using 59 PHA bins.
# Reduced chi-squared = 0.9593 for 57 degrees of freedom
# Null hypothesis probability = 5.625071e-01
Photon flux (15-150 keV) in 1 sec: 6.56033 ( -0.33336 0.33398 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.98907e-07 ( -2.68005e-08 2.69407e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 27.452 sec. to 28.452 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31252 ( -0.231008 0.360114 )
Epeak [keV] : 194.981 ( )
Norm@50keV : 6.46113E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.80 using 59 PHA bins.
# Reduced chi-squared = 0.9608 for 56 degrees of freedom
# Null hypothesis probability = 5.584751e-01
Photon flux (15-150 keV) in 1 sec: 4.74686 ( -0.55904 0.49126 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.92799e-07 ( -2.92347e-08 2.90562e-08 ) ergs/cm2
Time-resolved spectra
