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 -0.004 sec. to 0.100 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.12172 ( -0.271729 0.271481 )
Norm@50keV : 5.09355E-02 ( -0.00901583 0.00901223 )
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#Fit statistic : Chi-Squared = 74.54 using 59 PHA bins.
# Reduced chi-squared = 1.308 for 57 degrees of freedom
# Null hypothesis probability = 5.932664e-02
Photon flux (15-150 keV) in 0.104 sec: 0.185362 0.282082 0.181558 4.16980E-02 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 5.50102e-08 ( -1.05887e-08 1.06547e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.004 sec. to 0.100 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64229 ( -1.91988 3.35127 )
Epeak [keV] : 78.2964 ( -12.5723 41.0874 )
Norm@50keV : 0.755123 ( -0.76608 11.032 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.51 using 59 PHA bins.
# Reduced chi-squared = 1.206 for 56 degrees of freedom
# Null hypothesis probability = 1.394258e-01
Photon flux (15-150 keV) in 0.104 sec: 5.50945 ( -1.12171 1.12355 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.267e-08 ( -1.07439e-08 1.10013e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.450 sec. to 0.550 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.03707 ( -0.597945 0.607128 )
Norm@50keV : 5.68852E-03 ( -0.00201087 0.00200069 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.49 using 59 PHA bins.
# Reduced chi-squared = 1.079 for 57 degrees of freedom
# Null hypothesis probability = 3.185353e-01
Photon flux (15-150 keV) in 1 sec: 0.656421 ( -0.234463 0.236882 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.07267e-08 ( -2.2776e-08 2.32792e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.450 sec. to 0.550 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 9.99564 ( -8.75692 -9.99988 )
Epeak [keV] : 78.1791 ( -11.4832 20.361 )
Norm@50keV : 13.6082 ( -13.7034 45.1607 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.12 using 59 PHA bins.
# Reduced chi-squared = 1.002 for 56 degrees of freedom
# Null hypothesis probability = 4.703094e-01
Photon flux (15-150 keV) in 1 sec: 0.449918 ( -0.135169 0.208405 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.09612e-08 ( -1.64762e-08 2.14557e-08 ) ergs/cm2
Time-resolved spectra
