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 -0.576 sec. to 11.776 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.85543 ( -0.198802 0.189578 )
Norm@50keV : 8.70680E-03 ( -0.00110144 0.00107548 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 54.67 using 59 bins.
Reduced chi-squared = 0.959123
# Null hypothesis probability of 5.63e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 12.35 sec: 1.22661 ( -0.13008 0.13013 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.88819e-07 ( -1.23617e-07 1.25391e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.576 sec. to 11.776 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.62773 ( -0.635992 0.757967 )
Epeak [keV] : 74.5340 ( -68.6423 -74.5334 )
Norm@50keV : 1.16086E-02 ( -0.00614597 0.0179832 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 54.34 using 59 bins.
Reduced chi-squared = 0.970357
# Null hypothesis probability of 5.38e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 12.35 sec: 1.21690 ( -0.13323 0.13312 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.70883e-07 ( -1.33688e-07 1.34893e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.428 sec. to 1.428 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72248 ( -0.221043 0.212357 )
Norm@50keV : 2.78344E-02 ( -0.00410964 0.00404112 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 59.26 using 59 bins.
Reduced chi-squared = 1.03965
# Null hypothesis probability of 3.93e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 3.72639 ( -0.50296 0.50315 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.5733e-07 ( -3.91022e-08 3.94605e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.428 sec. to 1.428 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.14201 ( -0.718137 0.940202 )
Epeak [keV] : 69.2877 ( -21.3154 -69.288 )
Norm@50keV : 5.76171E-02 ( -0.0324273 0.12469 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.71 using 59 bins.
Reduced chi-squared = 1.03054
# Null hypothesis probability of 4.12e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 3.69668 ( -0.50567 0.50546 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.49569e-07 ( -4.0495e-08 4.09603e-08 ) ergs/cm2
Time-resolved spectra
