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 -19.224 sec. to 315.300 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.61914 ( -0.0803192 0.0798526 )
Norm@50keV : 1.98215E-03 ( -8.77709e-05 8.74555e-05 )
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#Fit statistic : Chi-Squared 60.42 using 59 bins.
Reduced chi-squared = 1.06
# Null hypothesis probability of 3.53e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 334.5 sec: 0.256257 ( -0.011703 0.011731 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.18765e-06 ( -2.90444e-07 2.91623e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -19.224 sec. to 315.300 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.40789 ( -0.248745 0.340438 )
Epeak [keV] : 142.140 ( -58.5391 -142.147 )
Norm@50keV : 2.52244E-03 ( -0.000599555 0.00116696 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 59.15 using 59 bins.
Reduced chi-squared = 1.05625
# Null hypothesis probability of 3.61e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 334.5 sec: 0.252950 ( -0.012668 0.012687 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.08492e-06 ( -3.30707e-07 3.2874e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 21.620 sec. to 22.620 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.40468 ( -0.182125 0.179708 )
Norm@50keV : 2.42206E-02 ( -0.00275519 0.00274811 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 67.27 using 59 bins.
Reduced chi-squared = 1.18018
# Null hypothesis probability of 1.66e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.95282 ( -0.33728 0.33776 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.33841e-07 ( -2.90598e-08 2.92767e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 21.620 sec. to 22.620 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.304777 ( -0.814139 0.990356 )
Epeak [keV] : 80.1835 ( -17.7422 78.3497 )
Norm@50keV : 8.36385E-02 ( -0.0495064 0.162849 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.69 using 59 bins.
Reduced chi-squared = 1.10161
# Null hypothesis probability of 2.80e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.84601 ( -0.34825 0.34772 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.21335e-07 ( -3.10432e-08 3.12456e-08 ) ergs/cm2
Time-resolved spectra
