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 -2.328 sec. to 0.360 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29672 ( -0.193882 0.194316 )
Norm@50keV : 6.17146E-03 ( -0.0006915 0.000689334 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.14 using 59 PHA bins.
# Reduced chi-squared = 1.073 for 57 degrees of freedom
# Null hypothesis probability = 3.297087e-01
Photon flux (15-150 keV) in 2.688 sec: 0.735836 ( -0.082071 0.082131 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.64078e-07 ( -2.09251e-08 2.11898e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.328 sec. to 0.360 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.03317 ( -0.432527 0.83299 )
Epeak [keV] : 186.076 ( -186.076 -186.076 )
Norm@50keV : 8.37288E-03 ( -0.00354554 0.012993 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.75 using 59 PHA bins.
# Reduced chi-squared = 1.085 for 56 degrees of freedom
# Null hypothesis probability = 3.086161e-01
Photon flux (15-150 keV) in 2.688 sec: 0.727900 ( -0.085148 0.084865 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.60568e-07 ( -2.33065e-08 2.31191e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -2.330 sec. to -1.330 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23598 ( -0.227381 0.229384 )
Norm@50keV : 8.69517E-03 ( -0.00116985 0.00116695 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.52 using 59 PHA bins.
# Reduced chi-squared = 1.202 for 57 degrees of freedom
# Null hypothesis probability = 1.410398e-01
Photon flux (15-150 keV) in 1 sec: 1.02611 ( -0.139127 0.13931 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.73554e-08 ( -1.32141e-08 1.33818e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.330 sec. to -1.330 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.480452 ( -0.853192 1.28895 )
Epeak [keV] : 103.409 ( -36.8302 -103.408 )
Norm@50keV : 2.05064E-02 ( -0.0124899 0.0650615 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.87 using 59 PHA bins.
# Reduced chi-squared = 1.194 for 56 degrees of freedom
# Null hypothesis probability = 1.515804e-01
Photon flux (15-150 keV) in 1 sec: 0.995346 ( -0.14691 0.145704 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.25277e-08 ( -1.49287e-08 1.49264e-08 ) ergs/cm2
Time-resolved spectra
