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 1.624 sec. to 267.996 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.72532 ( -0.0841517 0.0833578 )
Norm@50keV : 1.83911E-03 ( -8.86058e-05 8.82366e-05 )
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#Fit statistic : Chi-Squared = 70.96 using 59 PHA bins.
# Reduced chi-squared = 1.245 for 57 degrees of freedom
# Null hypothesis probability = 1.011420e-01
Photon flux (15-150 keV) in 266.4 sec: 0.246466 ( -0.011795 0.011819 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.52851e-06 ( -2.26568e-07 2.27629e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.624 sec. to 267.996 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.34163 ( -0.334473 0.362809 )
Epeak [keV] : 83.5640 ( -19.8877 191.003 )
Norm@50keV : 2.89137E-03 ( -0.000922551 0.00150532 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.09 using 59 PHA bins.
# Reduced chi-squared = 1.198 for 56 degrees of freedom
# Null hypothesis probability = 1.473971e-01
Photon flux (15-150 keV) in 266.4 sec: 0.241087 ( -0.012654 0.012666 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.38686e-06 ( -2.58154e-07 2.58015e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 8.408 sec. to 9.408 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.07164 ( -0.362549 0.395927 )
Norm@50keV : 8.37679E-03 ( -0.00207923 0.00204806 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.44 using 59 PHA bins.
# Reduced chi-squared = 1.131 for 57 degrees of freedom
# Null hypothesis probability = 2.324737e-01
Photon flux (15-150 keV) in 1 sec: 0.969134 ( -0.246242 0.249866 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.84016e-08 ( -2.12788e-08 2.13119e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.408 sec. to 9.408 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.487317 ( -1.6674 2.79888 )
Epeak [keV] : 92.3218 ( -28.1254 -92.3219 )
Norm@50keV : 4.07363E-02 ( -0.0407362 0.474174 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.03 using 59 PHA bins.
# Reduced chi-squared = 1.108 for 56 degrees of freedom
# Null hypothesis probability = 2.699571e-01
Photon flux (15-150 keV) in 1 sec: 0.927592 ( -0.248274 0.253708 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.46233e-08 ( -2.24348e-08 2.23314e-08 ) ergs/cm2
Time-resolved spectra
