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 -1.904 sec. to 126.756 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.78538 ( -0.163376 0.158192 )
Norm@50keV : 9.26392E-04 ( -9.55836e-05 9.4012e-05 )
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#Fit statistic : Chi-Squared = 46.50 using 59 PHA bins.
# Reduced chi-squared = 0.8157 for 57 degrees of freedom
# Null hypothesis probability = 8.384547e-01
Photon flux (15-150 keV) in 128.7 sec: 0.126945 ( -0.011231 0.011235 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.0984e-06 ( -1.1509e-07 1.17031e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.904 sec. to 126.756 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31245 ( -0.560203 0.676887 )
Epeak [keV] : 65.1245 ( -17.7633 -65.1243 )
Norm@50keV : 1.68831E-03 ( -0.000813865 0.0022343 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.62 using 59 PHA bins.
# Reduced chi-squared = 0.7968 for 56 degrees of freedom
# Null hypothesis probability = 8.629685e-01
Photon flux (15-150 keV) in 128.7 sec: 0.124520 ( -0.011622 0.011618 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04995e-06 ( -1.26914e-07 1.3053e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -1.804 sec. to -0.804 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.07186 ( -0.407558 0.356825 )
Norm@50keV : 3.88411E-03 ( -0.00112305 0.00108889 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.95 using 59 PHA bins.
# Reduced chi-squared = 1.052 for 57 degrees of freedom
# Null hypothesis probability = 3.691385e-01
Photon flux (15-150 keV) in 1 sec: 0.602773 ( -0.124739 0.124788 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.60048e-08 ( -9.23717e-09 9.71665e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.804 sec. to -0.804 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.048462 ( -2.09925 3.20872 )
Epeak [keV] : 35.9612 ( -16.2287 18.4743 )
Norm@50keV : 7.85554E-02 ( -0.0913179 8.14385 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.84 using 59 PHA bins.
# Reduced chi-squared = 1.015 for 56 degrees of freedom
# Null hypothesis probability = 4.435280e-01
Photon flux (15-150 keV) in 1 sec: 0.579797 ( -0.122775 0.124235 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.04586e-08 ( -7.56205e-09 9.9543e-09 ) ergs/cm2
Time-resolved spectra
