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 -14.060 sec. to 5.548 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.78325 ( -0.272508 0.261404 )
Norm@50keV : 2.94996E-03 ( -0.000526281 0.000514602 )
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#Fit statistic : Chi-Squared = 83.78 using 59 PHA bins.
# Reduced chi-squared = 1.470 for 57 degrees of freedom
# Null hypothesis probability = 1.199791e-02
Photon flux (15-150 keV) in 19.61 sec: 0.403910 ( -0.06264 0.062669 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.32988e-07 ( -9.56597e-08 9.78931e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -14.060 sec. to 5.548 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.158784 ( -1.88079 3.34509 )
Epeak [keV] : 43.5832 ( -9.18317 -43.3934 )
Norm@50keV : 2.85622E-02 ( -0.0305687 3.65817 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 81.79 using 59 PHA bins.
# Reduced chi-squared = 1.460 for 56 degrees of freedom
# Null hypothesis probability = 1.390034e-02
Photon flux (15-150 keV) in 19.61 sec: 0.382182 ( -0.068219 0.06875 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.36523e-07 ( -1.07097e-07 1.4995e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.516 sec. to 5.516 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.44713 ( -0.485558 0.480431 )
Norm@50keV : 9.29589E-03 ( -0.00225614 0.00222659 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.11 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 57 degrees of freedom
# Null hypothesis probability = 4.340790e-01
Photon flux (15-150 keV) in 1 sec: 1.14478 ( -0.285757 0.28618 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.90164e-08 ( -2.36913e-08 2.37683e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.516 sec. to 5.516 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.47029 ( -0.464583 0.729767 )
Epeak [keV] : 9999.35 ( -9999.36 -9999.36 )
Norm@50keV : 9.29888E-03 ( -0.00223654 0.0109629 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.13 using 59 PHA bins.
# Reduced chi-squared = 1.038 for 56 degrees of freedom
# Null hypothesis probability = 3.967386e-01
Photon flux (15-150 keV) in 1 sec: 1.16770 ( -0.306825 0.26753 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.22824e-08 ( -3.09307e-08 2.41133e-08 ) ergs/cm2
Time-resolved spectra
