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 -2.704 sec. to 1.368 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.751449 ( -0.214506 0.22918 )
Norm@50keV : 5.29051E-03 ( -0.000712003 0.000697735 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 54.21 using 59 bins.
Reduced chi-squared = 0.951053
# Null hypothesis probability of 5.80e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 4.072 sec: 0.609401 ( -0.077689 0.07827 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.57062e-07 ( -3.20697e-08 3.21842e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.704 sec. to 1.368 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.0455262 ( -0.867725 1.1695 )
Epeak [keV] : 161.653 ( -64.6433 -161.653 )
Norm@50keV : 1.09455E-02 ( -0.00591274 0.0178782 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 51.96 using 59 bins.
Reduced chi-squared = 0.927857
# Null hypothesis probability of 6.28e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 4.072 sec: 0.587961 ( -0.081304 0.081871 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.49861e-07 ( -3.4152e-08 3.37598e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.204 sec. to 0.796 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.830411 ( -0.226152 0.237274 )
Norm@50keV : 1.08310E-02 ( -0.00151184 0.00149737 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 53.35 using 59 bins.
Reduced chi-squared = 0.935965
# Null hypothesis probability of 6.13e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.24373 ( -0.17053 0.17117 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.24994e-07 ( -1.78766e-08 1.8004e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.204 sec. to 0.796 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.136557 ( -0.956426 1.25104 )
Epeak [keV] : 129.992 ( -43.3731 1795.5 )
Norm@50keV : 2.81848E-02 ( -0.0169593 0.0615694 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 50.36 using 59 bins.
Reduced chi-squared = 0.899286
# Null hypothesis probability of 6.87e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.19732 ( -0.17676 0.17724 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.19286e-07 ( -1.96836e-08 1.93736e-08 ) ergs/cm2
Time-resolved spectra
