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 -0.040 sec. to 0.352 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.525033 ( -0.337895 0.375533 )
Norm@50keV : 9.85348E-03 ( -0.00230442 0.00221817 )
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#Fit statistic : Chi-Squared = 65.37 using 59 PHA bins.
# Reduced chi-squared = 1.147 for 57 degrees of freedom
# Null hypothesis probability = 2.089210e-01
Photon flux (15-150 keV) in 0.392 sec: 1.16235 ( -0.237983 0.23992 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.12477e-08 ( -1.03559e-08 1.03814e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.040 sec. to 0.352 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.06455 ( -1.69615 2.97352 )
Epeak [keV] : 134.245 ( -43.6231 -134.239 )
Norm@50keV : 3.50950E-02 ( -0.0350991 0.227845 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.12 using 59 PHA bins.
# Reduced chi-squared = 1.127 for 56 degrees of freedom
# Null hypothesis probability = 2.391524e-01
Photon flux (15-150 keV) in 0.392 sec: 1.10558 ( -0.242598 0.24844 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.04586e-08 ( -1.09278e-08 1.07618e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.342 sec. to 0.658 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.126273 ( -0.492691 0.624273 )
Norm@50keV : 3.59574E-03 ( -0.00142443 0.00135952 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.79 using 59 PHA bins.
# Reduced chi-squared = 0.9436 for 57 degrees of freedom
# Null hypothesis probability = 5.964388e-01
Photon flux (15-150 keV) in 1 sec: 0.465484 ( -0.128917 0.132786 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.94128e-08 ( -1.48513e-08 1.48275e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.342 sec. to 0.658 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.29943 ( -1.70097 4.45375 )
Epeak [keV] : 175.187 ( -175.197 -175.197 )
Norm@50keV : 9.77773E-03 ( -0.00977693 0.13089 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.94 using 59 PHA bins.
# Reduced chi-squared = 0.9453 for 56 degrees of freedom
# Null hypothesis probability = 5.915685e-01
Photon flux (15-150 keV) in 1 sec: 0.451061 ( -0.12332 0.132928 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.93581e-08 ( -1.55898e-08 1.5194e-08 ) ergs/cm2
Time-resolved spectra
