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 -0.008 sec. to 0.548 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.42397 ( -0.244638 0.244088 )
Norm@50keV : 2.39932E-02 ( -0.00399338 0.00398172 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 64.37 using 59 bins.
Reduced chi-squared = 1.1293
# Null hypothesis probability of 2.34e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 0.556 sec: 2.93831 ( -0.4907 0.49153 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28299e-07 ( -2.29055e-08 2.31074e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.008 sec. to 0.548 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: 0.400334 ( -1.28481 1.80431 )
Epeak [keV] : 62.4757 ( -13.1064 40.669 )
Norm@50keV : 0.221521 ( -0.221653 1.78347 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.88 using 59 bins.
Reduced chi-squared = 1.03357
# Null hypothesis probability of 4.06e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 0.556 sec: 2.84932 ( -0.49707 0.4983 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15485e-07 ( -2.39226e-08 2.5138e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.230 sec. to 0.770 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.49865 ( -0.240385 0.236243 )
Norm@50keV : 1.72052E-02 ( -0.00286471 0.00284735 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 72.75 using 59 bins.
Reduced chi-squared = 1.27632
# Null hypothesis probability of 7.80e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.14716 ( -0.34649 0.34684 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.63271e-07 ( -2.9115e-08 2.95392e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.230 sec. to 0.770 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.37334 ( -1.58291 2.37601 )
Epeak [keV] : 52.9620 ( -7.7439 9.60793 )
Norm@50keV : 0.610603 ( -0.673718 11.394 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 59.98 using 59 bins.
Reduced chi-squared = 1.07107
# Null hypothesis probability of 3.34e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.02157 ( -0.34777 0.3512 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.36842e-07 ( -2.6579e-08 2.99672e-08 ) ergs/cm2
Time-resolved spectra
