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 -0.196 sec. to 10.204 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.85624 ( -0.264642 0.248946 )
Norm@50keV : 4.50367E-03 ( -0.000728237 0.000705369 )
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#Fit statistic : Chi-Squared = 61.30 using 59 PHA bins.
# Reduced chi-squared = 1.075 for 57 degrees of freedom
# Null hypothesis probability = 3.244095e-01
Photon flux (15-150 keV) in 10.4 sec: 0.634686 ( -0.085396 0.085482 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.30709e-07 ( -6.8221e-08 6.97097e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.196 sec. to 10.204 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.73621 ( -0.589797 1.10896 )
Epeak [keV] : 99.0622 ( -99.2768 -99.2915 )
Norm@50keV : 5.24359E-03 ( -0.00524051 0.0157673 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.26 using 59 PHA bins.
# Reduced chi-squared = 1.094 for 56 degrees of freedom
# Null hypothesis probability = 2.929956e-01
Photon flux (15-150 keV) in 10.4 sec: 0.631436 ( -0.089376 0.087885 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.25827e-07 ( -7.78558e-08 7.36015e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.216 sec. to 0.784 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72382 ( -0.1856 0.178161 )
Norm@50keV : 2.15935E-02 ( -0.00261545 0.00257985 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 82.58 using 59 PHA bins.
# Reduced chi-squared = 1.449 for 57 degrees of freedom
# Null hypothesis probability = 1.501478e-02
Photon flux (15-150 keV) in 1 sec: 2.89226 ( -0.31738 0.31757 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.99609e-07 ( -2.49665e-08 2.52757e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.216 sec. to 0.784 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.648154 ( -0.763361 0.900532 )
Epeak [keV] : 58.8106 ( -11.4416 33.6278 )
Norm@50keV : 8.11765E-02 ( -0.0487548 0.160043 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 76.46 using 59 PHA bins.
# Reduced chi-squared = 1.365 for 56 degrees of freedom
# Null hypothesis probability = 3.599775e-02
Photon flux (15-150 keV) in 1 sec: 2.80241 ( -0.32285 0.32335 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.86672e-07 ( -2.58446e-08 2.66571e-08 ) ergs/cm2
Time-resolved spectra
