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 -3.808 sec. to 23.056 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.5854 ( -0.195647 0.192991 )
Norm@50keV : 4.88852E-03 ( -0.000572479 0.000568387 )
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#Fit statistic : Chi-Squared = 74.12 using 59 PHA bins.
# Reduced chi-squared = 1.300 for 57 degrees of freedom
# Null hypothesis probability = 6.338809e-02
Photon flux (15-150 keV) in 26.86 sec: 0.625410 ( -0.072562 0.072701 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2304e-06 ( -1.53449e-07 1.54715e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.808 sec. to 23.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2377 ( -0.388476 0.885135 )
Epeak [keV] : 107.727 ( -50.7914 -107.732 )
Norm@50keV : 7.39500E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 73.51 using 59 PHA bins.
# Reduced chi-squared = 1.313 for 56 degrees of freedom
# Null hypothesis probability = 5.826590e-02
Photon flux (15-150 keV) in 26.86 sec: 0.617269 ( -0.075065 0.074826 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20068e-06 ( -1.68733e-07 1.67417e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.780 sec. to 2.780 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.49284 ( -0.384184 0.389031 )
Norm@50keV : 1.24468E-02 ( -0.00292938 0.00292564 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.32 using 59 PHA bins.
# Reduced chi-squared = 1.058 for 57 degrees of freedom
# Null hypothesis probability = 3.565690e-01
Photon flux (15-150 keV) in 1 sec: 1.55090 ( -0.38515 0.38737 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.18233e-07 ( -2.91448e-08 2.92459e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.780 sec. to 2.780 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.688695 ( -1.15442 3.1845 )
Epeak [keV] : 85.6629 ( -39.1718 -85.3819 )
Norm@50keV : 3.08357E-02 ( -0.0311119 0.670096 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.86 using 59 PHA bins.
# Reduced chi-squared = 1.069 for 56 degrees of freedom
# Null hypothesis probability = 3.376244e-01
Photon flux (15-150 keV) in 1 sec: 1.51360 ( -0.41867 0.40068 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.14601e-07 ( -3.06318e-08 3.07272e-08 ) ergs/cm2
Time-resolved spectra
