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 -0.060 sec. to 95.012 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.17156 ( -0.149173 0.152602 )
Norm@50keV : 1.53899E-03 ( -0.000126803 0.000126385 )
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#Fit statistic : Chi-Squared = 61.85 using 59 PHA bins.
# Reduced chi-squared = 1.085 for 57 degrees of freedom
# Null hypothesis probability = 3.070241e-01
Photon flux (15-150 keV) in 95.07 sec: 0.179957 ( -0.015571 0.01566 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.49676e-06 ( -1.31414e-07 1.32059e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.060 sec. to 95.012 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.16699 ( -0.202064 0.334844 )
Epeak [keV] : 1.00000E+04 ( -10000 -10000 )
Norm@50keV : 1.54658E-03 ( -0.000126215 0.000126035 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.88 using 59 PHA bins.
# Reduced chi-squared = 1.105 for 56 degrees of freedom
# Null hypothesis probability = 2.743960e-01
Photon flux (15-150 keV) in 95.07 sec: 0.180834 ( -0.017288 0.018823 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50226e-06 ( -1.69462e-07 1.59331e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.072 sec. to 0.928 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.802818 ( -0.0617769 0.062327 )
Norm@50keV : 0.104953 ( -0.00368044 0.00366314 )
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#Fit statistic : Chi-Squared = 49.54 using 59 PHA bins.
# Reduced chi-squared = 0.8691 for 57 degrees of freedom
# Null hypothesis probability = 7.481738e-01
Photon flux (15-150 keV) in 1 sec: 12.0611 ( -0.415 0.4153 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.22512e-06 ( -4.55601e-08 4.56589e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.072 sec. to 0.928 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.795095 ( -0.0625724 0.263483 )
Epeak [keV] : 9950.56 ( -9892.71 -9892.71 )
Norm@50keV : 0.105703 ( -0.0036492 0.0296862 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.53 using 59 PHA bins.
# Reduced chi-squared = 0.8844 for 56 degrees of freedom
# Null hypothesis probability = 7.167909e-01
Photon flux (15-150 keV) in 1 sec: 6.64938E-02 ( -0.0664938 0.0827652 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.66827e-08 ( 0 0 ) ergs/cm2
Time-resolved spectra