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 -2.068 sec. to 97.364 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.87756 ( -0.0821029 0.0811261 )
Norm@50keV : 4.26524E-03 ( -0.000193647 0.000192383 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 47.02 using 59 bins.
Reduced chi-squared = 0.824912
# Null hypothesis probability of 8.24e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 99.43 sec: 0.606395 ( -0.026342 0.026414 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.89931e-06 ( -1.76097e-07 1.77005e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.068 sec. to 97.364 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72688 ( -0.311201 0.324039 )
Epeak [keV] : 84.7894 ( -26.0645 -84.79 )
Norm@50keV : 5.11729E-03 ( -0.00153225 0.00239426 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 46.31 using 59 bins.
Reduced chi-squared = 0.826964
# Null hypothesis probability of 8.19e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 99.43 sec: 0.600161 ( -0.029039 0.029078 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.83979e-06 ( -2.12205e-07 2.10422e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 66.712 sec. to 67.712 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.5946 ( -0.112768 0.111434 )
Norm@50keV : 3.44685E-02 ( -0.00238807 0.00237525 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 42.82 using 59 bins.
Reduced chi-squared = 0.751228
# Null hypothesis probability of 9.18e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 4.42213 ( -0.29566 0.2959 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.22612e-07 ( -2.395e-08 2.41249e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 66.712 sec. to 67.712 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.939289 ( -0.4603 0.516183 )
Epeak [keV] : 77.5780 ( -16.3598 67.7537 )
Norm@50keV : 7.60060E-02 ( -0.0317919 0.0640536 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 36.65 using 59 bins.
Reduced chi-squared = 0.654464
# Null hypothesis probability of 9.79e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 4.31080 ( -0.30595 0.30585 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.06606e-07 ( -2.63854e-08 2.65748e-08 ) ergs/cm2
Time-resolved spectra
