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 0.824 sec. to 7.888 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.45446 ( -0.0641513 0.0639933 )
Norm@50keV : 4.16571E-02 ( -0.00154395 0.00154362 )
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#Fit statistic : Chi-Squared = 73.18 using 59 PHA bins.
# Reduced chi-squared = 1.284 for 57 degrees of freedom
# Null hypothesis probability = 7.315486e-02
Photon flux (15-150 keV) in 7.064 sec: 5.13949 ( -0.20121 0.20159 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.81398e-06 ( -1.11635e-07 1.11861e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.824 sec. to 7.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.665129 ( -0.290507 0.31054 )
Epeak [keV] : 91.1938 ( -11.9965 22.5833 )
Norm@50keV : 9.76520E-02 ( -0.0257198 0.0376971 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.32 using 59 PHA bins.
# Reduced chi-squared = 0.8807 for 56 degrees of freedom
# Null hypothesis probability = 7.240066e-01
Photon flux (15-150 keV) in 7.064 sec: 4.92336 ( -0.21357 0.21435 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.69297e-06 ( -1.21501e-07 1.214e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 3.260 sec. to 4.260 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.41557 ( -0.119694 0.119084 )
Norm@50keV : 5.61311E-02 ( -0.00405293 0.00404767 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.70 using 59 PHA bins.
# Reduced chi-squared = 0.9246 for 57 degrees of freedom
# Null hypothesis probability = 6.369916e-01
Photon flux (15-150 keV) in 1 sec: 6.86039 ( -0.5045 0.50516 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.40742e-07 ( -4.25577e-08 4.28106e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 3.260 sec. to 4.260 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.82991 ( -0.470887 0.527319 )
Epeak [keV] : 105.275 ( -27.7522 187.923 )
Norm@50keV : 0.108141 ( -0.0434068 0.0829817 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.06 using 59 PHA bins.
# Reduced chi-squared = 0.8583 for 56 degrees of freedom
# Null hypothesis probability = 7.656750e-01
Photon flux (15-150 keV) in 1 sec: 6.71145 ( -0.51899 0.51907 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.24735e-07 ( -4.51893e-08 4.51536e-08 ) ergs/cm2
Time-resolved spectra
