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 -0.224 sec. to 2.776 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.66342 ( -0.362037 0.340055 )
Norm@50keV : 2.35983E-03 ( -0.00054713 0.000531052 )
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#Fit statistic : Chi-Squared = 71.20 using 59 PHA bins.
# Reduced chi-squared = 1.249 for 57 degrees of freedom
# Null hypothesis probability = 9.775051e-02
Photon flux (15-150 keV) in 3 sec: 0.309525 ( -0.061731 0.061735 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.5766e-08 ( -1.57751e-08 1.6379e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.224 sec. to 2.776 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.405952 ( -1.71164 2.76068 )
Epeak [keV] : 53.9380 ( -12.2097 -53.8418 )
Norm@50keV : 1.22463E-02 ( -0.0124021 0.480965 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.65 using 59 PHA bins.
# Reduced chi-squared = 1.244 for 56 degrees of freedom
# Null hypothesis probability = 1.038354e-01
Photon flux (15-150 keV) in 3 sec: 0.295733 ( -0.06447 0.064633 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.75229e-08 ( -1.63405e-08 1.96227e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.776 sec. to 1.776 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.86176 ( -0.366829 0.331047 )
Norm@50keV : 3.65040E-03 ( -0.000954378 0.000931508 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.99 using 59 PHA bins.
# Reduced chi-squared = 1.210 for 57 degrees of freedom
# Null hypothesis probability = 1.326098e-01
Photon flux (15-150 keV) in 1 sec: 0.515591 ( -0.10803 0.108072 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.3556e-08 ( -8.49087e-09 8.89911e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.776 sec. to 1.776 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.864794 ( -1.87241 2.86391 )
Epeak [keV] : 43.6381 ( -8.58715 13.541 )
Norm@50keV : 0.133775 ( -0.139367 5.20781 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.89 using 59 PHA bins.
# Reduced chi-squared = 1.105 for 56 degrees of freedom
# Null hypothesis probability = 2.741126e-01
Photon flux (15-150 keV) in 1 sec: 0.492215 ( -0.106318 0.10685 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.89248e-08 ( -6.88995e-09 8.02908e-09 ) ergs/cm2
Time-resolved spectra
