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 -20.076 sec. to 45.812 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.66195 ( -0.124629 0.122695 )
Norm@50keV : 3.70910E-03 ( -0.000266941 0.000264311 )
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#Fit statistic : Chi-Squared = 32.69 using 59 PHA bins.
# Reduced chi-squared = 0.5736 for 57 degrees of freedom
# Null hypothesis probability = 9.959904e-01
Photon flux (15-150 keV) in 65.89 sec: 0.486261 ( -0.032081 0.032107 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.2706e-06 ( -1.74122e-07 1.76379e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -20.076 sec. to 45.812 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.47476 ( -0.294963 0.52369 )
Epeak [keV] : 129.694 ( -65.495 -129.783 )
Norm@50keV : 4.67127E-03 ( -0.00131536 0.00413713 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 32.25 using 59 PHA bins.
# Reduced chi-squared = 0.5758 for 56 degrees of freedom
# Null hypothesis probability = 9.954661e-01
Photon flux (15-150 keV) in 65.89 sec: 0.481207 ( -0.034606 0.034418 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.22346e-06 ( -2.10756e-07 2.07959e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.064 sec. to 1.064 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.03757 ( -0.294545 0.307038 )
Norm@50keV : 1.29281E-02 ( -0.00221503 0.00220512 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.03 using 59 PHA bins.
# Reduced chi-squared = 1.036 for 57 degrees of freedom
# Null hypothesis probability = 4.011369e-01
Photon flux (15-150 keV) in 1 sec: 1.49181 ( -0.26069 0.26189 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.37997e-07 ( -2.54095e-08 2.56055e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.064 sec. to 1.064 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.656397 ( -0.643336 1.661 )
Epeak [keV] : 205.140 ( -205.094 -205.094 )
Norm@50keV : 1.90279E-02 ( -0.00806412 0.071285 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.77 using 59 PHA bins.
# Reduced chi-squared = 1.049 for 56 degrees of freedom
# Null hypothesis probability = 3.744519e-01
Photon flux (15-150 keV) in 1 sec: 1.46871 ( -0.27611 0.27134 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35838e-07 ( -2.70603e-08 2.66121e-08 ) ergs/cm2
Time-resolved spectra
