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 -0.264 sec. to 1.196 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.05057 ( -0.266097 0.275885 )
Norm@50keV : 5.54247E-03 ( -0.000843977 0.000840262 )
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#Fit statistic : Chi-Squared = 62.32 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 57 degrees of freedom
# Null hypothesis probability = 2.926559e-01
Photon flux (15-150 keV) in 1.46 sec: 0.640162 ( -0.099827 0.100347 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.59949e-08 ( -1.40363e-08 1.41394e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.264 sec. to 1.196 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.745243 ( -0.542066 1.22439 )
Epeak [keV] : 243.930 ( -243.88 -243.88 )
Norm@50keV : 7.50237E-03 ( -0.00346295 0.0157108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.05 using 59 PHA bins.
# Reduced chi-squared = 1.108 for 56 degrees of freedom
# Null hypothesis probability = 2.692739e-01
Photon flux (15-150 keV) in 1.46 sec: 0.631286 ( -0.104663 0.103998 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.50105e-08 ( -1.45846e-08 1.45169e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.116 sec. to 1.116 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.924194 ( -0.26824 0.283785 )
Norm@50keV : 6.68892E-03 ( -0.00105681 0.00104246 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.09 using 59 PHA bins.
# Reduced chi-squared = 0.8787 for 57 degrees of freedom
# Null hypothesis probability = 7.298975e-01
Photon flux (15-150 keV) in 1 sec: 0.767991 ( -0.121163 0.121999 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.43807e-08 ( -1.19584e-08 1.20245e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.116 sec. to 1.116 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.574966 ( -0.585752 1.33019 )
Epeak [keV] : 250.849 ( -250.441 -250.441 )
Norm@50keV : 9.32436E-03 ( -0.00354924 0.0203493 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.77 using 59 PHA bins.
# Reduced chi-squared = 0.8888 for 56 degrees of freedom
# Null hypothesis probability = 7.082483e-01
Photon flux (15-150 keV) in 1 sec: 0.755856 ( -0.127607 0.12643 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.35377e-08 ( -1.24111e-08 1.23182e-08 ) ergs/cm2
Time-resolved spectra
